Summary NKU: MSN 629 Quiz 3 Study Guide_ Complete Updated 2025.

1 Quiz 3 Study Guide Skin Lesions: External Clues to Internal Problem Box 9.8 p. 157 Many systemic conditions or disorders may present congenital external clues that are apparent on physical examination. The following are a few examples of cutaneous markers that may signal underlying disease. A thorough evaluation is necessary, although some clues may be isolated findings and may require no intervention, follow-up, or treatment. • Faun tail nevus: Tuft of hair overlying the spinal column at birth, usually in the lumbosacral area; may be associated with spina bifida occulta. • Café au lait macules: Flat, evenly pigmented spots varying in color from light brown to dark brown or black in darker skin; larger than 5 mm in diameter; present at birth or shortly thereafter; may be associated with neurofibromatosis or miscellaneous other conditions including pulmonary stenosis, temporal lobe dysrhythmia, and tuberous sclerosis. • Freckling in the axillary or inguinal area: Multiple flat pigmented macules associated with neurofibromatosis; may occur in conjunction with café au lait macules. • Facial port-wine stain: Usually at least one eyelid and/or the forehead of one side of the face are affected. It may be associated with ocular defects, most notably glaucoma; or may be accompanied by angiomatous malformation of the meninges (Sturge-Weber syndrome), resulting in atrophy and calcification of the adjacent cerebral cortex. • Port-wine stain of limb and/or trunk: When accompanied by varicosities and hypertrophy of underlying soft tissues and bones, may be associated with orthopedic problems (Klippel-TrenaunayWeber syndrome). • Supernumerary nipples: Congenital accessory nipples with or without glandular tissue, located along the mammary ridge (see Chapter 17); may be associated with renal abnormalities, especially in the presence of other minor anomalies. • “Hair collar” sign: A ring of long, dark, coarse hair surrounding a midline scalp nodule in infants is usually an isolated cutaneous anomaly that may indicate neural tube closure defects of the scalp. Abnormalities Skin, Hair Nails Page 163-170 Eczematous Dermatitis Most common inflammatory skin disorder; several forms, including irritant contact dermatitis, allergic contact dermatitis, and atopic dermatitis. Pathophysiology • Common factor of the various forms are intercellular edema and epidermal breakdown. • Eczematous dermatitis has three stages: acute, subacute, and chronic. • Itch-scratch cycle perpetuates the rash. • Excoriation from scratching predisposes to infection and causes crust formation (Fig. 9.44). Subjective Data • Itching is typically present. • Those with atopic dermatitis often report allergy history (allergic rhinitis, asthma). • For irritant or allergic contact, exposure history is important. Objective Data • Acute phase characterized by erythematous, pruritic, weeping vesicles • Subacute eczema characterized by erythema and scaling • Chronic stage characterized by thick, lichenified, pruritic plaques • Atopic dermatitis: during childhood, lesions involve flexures, the nape, and the dorsal aspects of the limbs; in adolescence and adulthood, lichenified plaques affect the flexures, head, and neck2 Quiz 3 Study Guide Folliculitis Inflammation and infection of the hair follicle and surrounding dermis. Pathophysiology • Presence of inflammatory cells within the wall and ostia of the hair follicle creates a follicular-based pustule. • Inflammation can be either superficial or deep; deep folliculitis can result from chronic lesions of superficial folliculitis or from lesions that are manipulated. • Persistent or recurrent lesions may result in scarring and permanent hair loss. • Sometimes due to a bacterial (e.g. staphylococcus) or yeast infection. Subjective Data • Acute onset of papules and pustules associated with pruritus or mild discomfort; may have pain with deep folliculitis • Risk factors: frequent shaving, immunosuppression, hot tubs without adequate chlorine, preexisting dermatoses, long-term antibiotic use, occlusive clothing and/or occlusive dressings, exposure to hot humid temperatures, diabetes mellitus, obesity, and use of EGFR (epithelial growth factor receptor) inhibitor medications Objective Data • Primary lesion is a small pustule 1–2 cm in diameter that is located over a pilosebaceous orifice and may be perforated by a hair. • Pustule may be surrounded by inflammation or nodular lesions; after the pustule ruptures, a crust forms (Fig. 9.45). • May have suppurative drainage with deep folliculitis. • Any hair-bearing site can be affected; the sites most often involved are the face, scalp, thighs, axilla, and inguinal area. Furuncle (Boil) A deep-seated infection of the pilosebaceous unit. Pathophysiology • Staphylococcus aureus is the most common organism. • Initially, a small perifollicular abscess that spreads to the surrounding dermis and subcutaneous tissue. • May occur singly or in multiples; when infection involves several adjacent follicles, a coalescent purulent mass or carbuncle forms. Subjective Data • Acute onset of tender red nodule with center filled with pus. Objective Data • Skin is red, hot, and tender. • Center of the lesion is purulent and forms a core that may rupture spontaneously or require surgical incision (Fig. 9.46). • Sites commonly involved are the face and neck, arms, axillae, breasts, thighs, and buttocks. Cellulitis Diffuse, acute, infection of the skin and subcutaneous tissue.3 Quiz 3 Study Guide Pathophysiology • Majority of cases caused by Streptococcus pyogenes or Staphylococcus aureus. Subjective Data • Break in the skin, such as a fissure, cut, laceration, insect bite, or puncture wound • Pain and swelling at the site • May have fever Objective Data • Skin is red, hot, tender, and indurated; borders are not well demarcated (Fig. 9.47). • Lymphangitic streaks and regional lymphadenopathy may be present. • Rare to have bilateral cellulitis. Tinea (Dermatophytosis) Group of noncandidal fungal infections that involve the stratum corneum, nails, or hair. Pathophysiology • Infection by dermatophytes, typically acquired by direct contact with infected humans or animals; invade the skin and survive on dead keratin. • Lesions are usually classified according to anatomic location and can occur on nonhairy parts of the body (tinea corporis), on the groin and inner thigh (tinea cruris), on the scalp (tinea capitis), on the feet (tinea pedis), and on the nails (tinea unguium). Subjective Data • May report pruritus. • May report hair breaking. • Nail changes accompany onychomycosis. Objective Data • While often annular, lesions can vary in appearance and may be papular, pustular, vesicular, erythematous, or scaling (Fig. 9.48). • Secondary bacterial infection may be present. • Microscopic examination of skin scraping with potassium hydroxide (KOH) solution shows presence of hyphae. • Infected nails are yellow and thick and may separate from the nail bed. Pityriasis Rosea Self-limiting inflammation of unknown cause. Pathophysiology • Possible infectious etiology (Drago et al., 2015), likely herpesvirus (HHV)-6 or HHV-7 • Not contagious Subjective Data • Sudden onset with occurrence of a primary (herald) oval or round plaque. • Herald lesion is often missed. • Eruption occurs 1–3 weeks later and lasts for several weeks. • Pruritus may be present with the generalized eruption. • Often occurs in young adults during the spring time. Objective Data4 Quiz 3 Study Guide • Lesions are usually oval, pale, erythematous, flat-topped papules and plaques with fine scaling (Fig. 9.49). • Lesions develop on the extremities and trunk; palms and soles are not involved, and facial involvement is rare. • Trunk lesions are characteristically distributed in parallel alignment following the skin tension lines in a Christmas tree–like pattern. Psoriasis Chronic and recurrent disease of keratinocyte proliferation. Pathophysiology • Multifactorial origin with genetic component and immune regulation • Characterized by increased epidermal cell turnover, increased numbers of epidermal stem cells, and abnormal differentiation of keratin expression leading to thickened skin with copious scale • Related to tumor necrosis factor (TNF)-alpha Subjective Data • May have pruritus • Concerns about appearance • Does not typically get superinfected Objective Data • Characterized by well-circumscribed, dry, silvery, scaling papules and plaques (Fig. 9.50). • Lesions commonly occur on the back, buttocks, extensor surfaces of the extremities, and the scalp. • Can be associated with psoriatic arthritis in up to 30% of patients. • May have pitting nail involvement. Rosacea Chronic inflammatory skin disorder. Pathophysiology • Cause unknown; occurs most often in persons with a fair complexion • Lasts for years, with episodes of activity followed by quiescent periods of variable length Subjective Data • Itching is absent. • Many patients report a stinging pain associated with flushing episodes. • Common triggers are exposure to the sun, cold weather, sudden emotion (e.g., laughter or embarrassment), hot beverages, spicy foods, and alcohol consumption. Objective Data • Eruptions appear on the forehead, cheeks, nose, and occasionally about the eyes. • Characterized by telangiectasia, erythema, papules, and pustules that occur particularly in the central area of the face (Fig. 9.51). • Although rosacea resembles acne, comedones are not present. • Tissue hypertrophy of the nose (rhinophyma) may occur, characterized by sebaceous hyperplasia, redness, prominent vascularity, and swelling of the skin of the nose (Fig. 9.52). Herpes Zoster (Shingles) Varicella-zoster viral (VZV) infection.5 Quiz 3 Study Guide Pathophysiology • VZV morphologically and antigenically identical to the virus causing varicella (chickenpox) • Dormant viral particles (since the original episode of varicella) in the posterior spinal ganglia or cranial sensory ganglia become activated and spread along the nerve Subjective Data • Pain, itching, or burning of the dermatome area usually precedes eruption by 4–5 days. • After eruption resolves, there may be persistent pain called postherpetic neuralgia. Objective Data • Single dermatome that consists of red, swollen plaques or vesicles that become filled with purulent fluid (Fig. 9.53) • Does not cross midline • Can still occur in immunized patients • Disseminated lesions in immunosuppressed or older adults Herpes Simplex Infection by herpes simplex virus (HSV). Pathophysiology • Two virus types cause the infection: type 1, usually associated with oral infection, and type 2, with genital infection. • Crossover infections are becoming common. Subjective Data • Tenderness, pain, paresthesia, or mild burning at the infected site before onset of the lesions Objective Data • Grouped vesicles appear on an erythematous base and then erode, forming a crust (Fig. 9.54). • Lesions last 2–6 weeks. • Can occur anywhere on the body. Lyme Disease A tick-borne disease that can lead to multisystemic infection. Pathophysiology • Spirochetal infection caused by Borrelia burgdorferi • Most common tick-borne disease in the United States • The spirochete deposited by the tick into the skin rather than directly into the bloodstream. • Three phases of the disease are recognized: early localized, early disseminated, and late disease. • The objective clinical manifestations are thought to be due to an inflammatory response to live spirochetes or to their antigens. Subjective Data • Exposure to ticks • Constitutional symptoms of fatigue, anorexia, and headache may develop. • Expanding rash Objective Data6 Quiz 3 Study Guide • Early localized infection typically manifested by a single erythema migrans skin lesion, a flat to slightly raised, erythematous skin lesion (usually ≥5 cm in diameter) that is round or oval in shape, with central clearing (Fig. 9.55) (classic target or bull’s-eye appearance). • Early disseminated infection is usually manifested by multiple erythema migrans skin lesions, by neurologic symptoms such as facial palsy, meningitis, or encephalitis, or by symptoms of carditis such as lightheadedness, palpitations, dyspnea, chest pain, or syncope. • Late disease usually manifested by arthritis atrophicans or atrophic dermatitis. Skin: Malignant/Neoplastic Abnormalities Page 171-172 Basal Cell Carcinoma The most common form of skin cancer. Pathophysiology • Arises from the basal layer of the epidermis • Occurs in various clinical forms including nodular, pigmented, cystic, sclerosing, and superficial • Occurs most frequently on exposed parts of the body—the face, ears, neck, scalp, shoulders Subjective Data • Persistent sore or lesion that has not healed • May have crusting • May itch Objective Data • Shiny nodule that is pearly or translucent; may be pink, red, or white, tan, black, or brown (Fig. 9.58) • Open sore; may have crusting; may bleed • Reddish patch or irritated area, frequently occurring on the face, chest, shoulders, arms, or legs • Pink growth with a slightly elevated rolled border and a crusted indentation in the center; as the growth slowly enlarges, tiny blood vessels may develop on the surface. • Scar-like area that is white, yellow, or waxy and often has poorly defined borders; the skin appears shiny and taut. Squamous Cell Carcinoma Second most common form of skin cancer. Pathophysiology • This malignant tumor arises in the epithelium and has squamous differentiation. • Lesions occur most commonly in sun-exposed areas, particularly the scalp, back of hands, lower lip, and ear; the rim of the ear and the lower lip are especially vulnerable. Subjective Data • Persistent sore or lesion that has not healed or that has grown in size • May have crusting and/or bleeding Objective Data • Elevated growth with volcano-type pattern (Fig. 9.59) • Wartlike growth; may have crusting, may bleed • Scaly red patch with irregular borders may have crusting and may bleed • Open sore; may have crusting Malignant Melanoma7 Quiz 3 Study Guide Lethal form of skin cancer that develops from melanocytes. Pathophysiology • Melanocytes migrate into the skin, eye, central nervous system, and mucous membrane during fetal development. • Less than half of the melanomas develop from nevi; the majority arise de novo from melanocytes. • The exact cause of malignancy is not known; heredity, hormonal factors, ultraviolet light exposure, or an autoimmunologic effect may contribute to causation. Subjective Data • New nevus or preexisting nevus that has changed or is changing • New pigmented lesion that has irregularities (Fig. 9.60) • History of melanoma • History of atypical nevi • Family history of melanoma (first-degree relative) • Significant sunlight or tanning bed use Objective Data • ABCDE changes in nevi (Fig. 9.61) • A Asymmetry of lesion: one-half of a nevus or birthmark does not match the other • B Borders: edges are irregular, ragged, notched, or blurred. Pigment may be streaming from the border. • C Color: the color is not the same all over and may have differing shades of brown or black, sometimes with patches of red, white, or blue. • D Diameter: the diameter is 6 mm (about the size of a pencil eraser) or is growing larger. • E Evolution: changes seen in existing pigmented lesions, particularly in a nonuniform, asymmetric manner. Actinic Keratosis p 187 Atypical squamous cells confined to the upper layers of epidermis Pathophysiology • Occurs secondary to chronic sun damage • Most lesions remain superficial; lesions can progress into squamous cell carcinoma over time. Subjective Data • History of chronic sun exposure • Increasing number of lesions with age Objective Data • Raised, gritty, erythematous lesion that is usually with an irregular, rough surface • Lesion is most common on the dorsal surface of the hands, arms, neck, and face (Fig. 9.88). Lymph nodes Page 190-191 Lymph nodes are discrete structures surrounded by a capsule composed of connective tissue and a few elastic fibrils. Lymph nodes usually occur in groups. Superficial nodes are located in subcutaneous connective tissues, and deeper nodes lie beneath the fascia of muscles and within the various body cavities. The nodes are numerous and tiny, but some of them may have diameters as large as 0.5 to 1 cm. They defend against the invasion of microorganisms and other particles with filtration and phagocytosis, and they aid in the maturation of lymphocytes and monocytes.8 Quiz 3 Study Guide9 Quiz 3 Study Guide Lymphatic system Abnormalities 200-207 Acute Lymphangitis Inflammation of one or more lymphatic vessels Pathophysiology • Pathogenic organisms enter the lymphatic vessels directly through a wound or as a complication of infection and produce a local inflammatory response. • Inflammation or infection then extends proximally toward regional lymph nodes. Subjective Data • Enlarged lymph node • Pain, malaise, possibly fever • Minor trauma to the skin distal to the area of infection Objective Data • Red streaks in the skin after the course of the lymphatic collecting duct • Appears as a tracing of rather fine lines streaking up the extremity • Sometimes indurated and palpable to gentle touch • Look distal to the inflammation for sites of infection, particularly between digits Acute Suppurative Lymphadenitis Infection and inflammation of a lymph node; may affect a single or localized group of nodes Pathophysiology • Most commonly caused by group A beta-hemolytic streptococci and coagulase-positive staphylococcal infection • Other pathogens may include actinomycotic adenitis as a result of dental disease; mycobacterial lymphadenitis in the presence of the tuberculosis organism; Pasteurella multocida infection at the site of a scratch or bite from a dog or cat • Lymph nodes enlarged because of the cellular infiltration and edema • Nodes tender because of distention of the capsule • Acute lymphadenitis most often seen in the cervical region due to microbial drainage from infections of the teeth or tonsils and in the axillary or inguinal regions secondary to infections in the extremities • Systemic viral infections (particularly in children) and bacteremia often produce generalized lymphadenopathy.10 Quiz 3 Study Guide Subjective Data • Enlarged lymph nodes • Pain from enlarged lymph nodes Objective Data • Involved node usually firm and tender • Overlying tissue edematous; skin appears erythematous, usually within 72 hours • When abscess formation is extensive, nodes fluctuant • Mycobacterial adenitis characterized by an inflammation without warmth that may or may not be slightly tender Lymphedema Edematous swelling due to excess accumulation of lymph fluid in tissues caused by inadequate lymph drainage Pathophysiology • Result of protein-rich interstitial volume overload, secondary to lymph drainage failure • Four major physiologic mechanisms: increased blood capillary hydrostatic pressure, decreased plasma protein concentration, increased blood permeability, and blockage of lymph return • Primary lymphedema: hypoplasia and maldevelopment of the lymphatic system; can manifest in infants or later; termed praecox in adolescence and tarda in patients approaching 40 years of age • Secondary: acquired damage to regional lymph nodes—pressure from tumors, scar tissue after radiation, or surgical removal of lymph nodes Subjective Data • Painless swelling of a limb; unilateral or bilateral • Onset usually gradual • History of trauma, surgery, or radiation to a regional area • Travel to areas where filariasis is common • Family history of leg swelling Objective Data • Swelling and often grotesque distortion of the extremities (Fig. 10.23) • Lymphedema may or may not pit. • Overlying skin eventually thickens and feels tougher than usual • Primary lymphedema often apparent at birth and most often involves the legs, particularly the dorsum of the foot; the degree varies with the severity and distribution of the abnormality and may not appear until young adulthood Lymphangioma/Cystic Hygroma Congenital malformation of dilated lymphatics Pathophysiology • Results from a failure of complete development and subsequent obstruction of the lymphatic system; commonly found in the neck Subjective Data • Painless cystic masses • Usually manifest during the first year of life and often enlarged after an upper respiratory infection • Asymptomatic when in the posterior triangle of the neck, but if found anteriorly, may cause airway or swallowing problems11 Quiz 3 Study Guide Objective Data • Soft, non-tender, and easily compressible spongy fluid-containing mass without discrete margins • Most present at birth and apparent early in life, usually in the neck or axilla, less commonly in the chest or extremities • May be large enough to distort face and neck • Diagnosis through physical examination and imaging studies (ultrasound, computed tomography, or magnetic resonance imaging), which show a thin-walled, multiloculated cystic mass Lymphatic Filariasis (Elephantiasis) Massive accumulation of lymphedema throughout the body; the most common cause of secondary lymphedema worldwide Pathophysiology • Results from widespread inflammation and obstruction of the lymphatics by the filarial worms Wuchereria bancrofti or Brugia malayi; transmitted by mosquitoes • Adequate drainage is prevented, and the patient becomes more susceptible to infection, cellulitis, and fibrosis • The term elephantiasis often incorrectly used to describe the result of any obstruction, congenital or acquired. Subjective Data • Swelling of limb or body area • Travel to infected areas: Asia, Africa, the Western Pacific, India, Philippines • Many patients are asymptomatic, but some may develop fever with lymphangitis and lymphadenitis, chronic pulmonary infection, and progressive lymphedema Objective Data • Lymphedema of the entire arm or leg; the genital regions (vulva, scrotum, breasts) • Diagnosis can be made by identification of microfilariae microscopically in blood Non-Hodgkin Lymphoma Malignant neoplasm of the lymphatic system and the reticuloendothelial tissues Pathophysiology • Non-Hodgkin lymphomas occur most often in lymph nodes in the chest, neck, abdomen, tonsils, and skin; they may also develop in sites other than lymph nodes such as the digestive tract, central nervous system, and around the tonsils. • Most arise in B cells; the rest occur in T cells • Histologically, their cells are often undifferentiated but resemble lymphocytes, histiocytes, or plasma cells. Subjective Data • Painless enlarged lymph node(s) • Fever, weight loss, night sweats, abdominal pain, or fullness • Family history of non-Hodgkin lymphomas Objective Data • Nodes may be localized in the posterior cervical triangle or may become matted, crossing into the anterior triangle. • Nodes usually well defined and solid12 Quiz 3 Study Guide • Cannot distinguish the findings of these conditions from those in Hodgkin lymphoma through physical examination alone Hodgkin Lymphoma Malignant lymphoma Pathophysiology • Unknown etiology, several subtypes • Starts in a single node or chain and spreads to contiguous lymph nodes, spleen, liver, and bone marrow • Neoplastic giant cells release factors that induce the accumulation of reactive lymphocytes, macrophages, and granulocytes. • Occurs in all races, generally in late adolescence and young adulthood, although it also occurs in people older than 50 years; most often, Hodgkin lymphoma starts in B-cell lymphocytes located in lymph nodes in the neck area, although any lymph node may be the site of initial disease. Subjective Data • Painless enlarged lymph nodes • May have abdominal pain, sometimes fever • May have history of infectious mononucleosis Objective Data • Clinical presentation variable • Most commonly, painless enlargement of the cervical lymph nodes, often in the posterior triangle, that is generally asymmetric and progressive (Fig. 10.24) • Nodes sometimes matted and firm, almost rubbery • Usually asymmetric; may occasionally be enlarged in similar patterns on both sides of the body • Nodal size may fluctuate Epstein-Barr Virus Mononucleosis Infectious mononucleosis Pathophysiology • Initially infects oral epithelial cells; after intracellular viral replication and cell lysis with release of new virions, virus spreads to contiguous structures such as the salivary glands, with eventual viremia and infection of the entire lymphoreticular system, including the liver and spleen • Incubation period of infectious mononucleosis in adolescents is 30–50 days Subjective Data • Malaise, fatigue, acute or prolonged (longer than 1 week) fever, headache, sore throat, nausea, abdominal pain, and myalgia • Prodromal period may last 1–2 weeks Objective Data • Generalized lymphadenopathy most commonly in the anterior and posterior cervical nodes and the submandibular lymph nodes and less commonly in the axillary and inguinal lymph nodes • Epitrochlear lymphadenopathy is particularly suggestive of infectious mononucleosis • Hepatomegaly; symptomatic hepatitis or jaundice is uncommon, but elevated liver enzymes are common. • Splenomegaly to 2–3 cm below the costal margin is typical; massive enlargement is uncommon • Moderate to severe pharyngitis with tonsillar enlargement, occasionally with exudates13 Quiz 3 Study Guide • Petechiae at the junction of the hard and soft palate frequently seen • Diagnosis with mononucleosis spot test Toxoplasmosis Zoonosis, caused by the parasite Toxoplasma gondii Pathophysiology • Ingestion or inhalation of oocysts in soil/fomites, undercooked meat, or raw eggs; cat feces or litter • Infection persists for life without signs of disease. • In immunosuppressed persons, quiescent parasites multiply, resulting in neurologic disease or other organ manifestations. • May cause serious congenital infection if exposed during pregnancy, particularly in the first trimester; transmitted directly from pregnant mother to fetus Subjective Data • No significant symptoms • History of eating raw or rare meat or uncooked eggs • History of direct contact with cat feces, cleaning the litter box, gardening in feces-contaminated soil Objective Data • Single node, chronically enlarged and non-tender • Node is usually in the posterior cervical chain Roseola Infantum (HHV-6) Infection by human herpes virus 6 Pathophysiology • Common in infancy with peak age of acquisition 2 years • Virus present in the saliva of most adults and is readily transmitted by oral secretions • Latency permits persistence of the virus in the presence of a fully developed immune response and allows lifelong infection of the host. • Through periodic reactivation of latent virus and the production of recurrent infection; virus shedding occurs at intervals throughout life, allowing the virus to be spread to new susceptible hosts Subjective Data • Fever—usually high grade and persistent over 3–4 days • Sometimes associated with a mild respiratory illness and lymphadenopathy Objective Data • Adenopathy, discrete and not tender, involves the occipital and postauricular chains and may last for some time • When the fever diminishes, a morbilliform fine maculopapular rash occurs, spreading from the trunk to the extremities; the child begins feeling much better Herpes Simplex (HSV) Infection by human herpes virus 1 (HSV-1) or human herpes virus 2 (HSV-2) Pathophysiology • Transmitted by oral secretions, genital secretions, and close contact • HSV causes lytic infection of fibroblasts and epithelial cells, and establishes latent infection in neurons; HSV-1 has predilection for oropharyngeal infection and HSV-2 for genital infection;14 Quiz 3 Study Guide although both viruses can infect and produce latent infection at either site, reactivation of each is most common at the preferred site. Subjective Data • Burning, itching lesions • May report enlarged lymph nodes Objective Data • Discrete labial and gingival vesicles or ulcers (Fig. 10.25) • May have enlargement of the anterior cervical and submandibular nodes • These nodes tend to be somewhat firm, quite discrete, movable, and tender; the frequency of this condition and the symptoms are generally sufficient to establish the diagnosis; a viral culture can be obtained if necessary Cat Scratch Disease A common cause of subacute or chronic lymphadenitis in children Pathophysiology • Caused mainly by Bartonella henselae and Bartonella clarridgeiae; usually follows a bite, scratch, or other penetrating injury from a kitten or cat; the organisms, however, rarely cause illness in the cat Subjective Data • Bite, scratch, or wound from cat or kitten • Inoculation lesion: a papule or pustule lasts 3–5 days and then becomes vesicular and crusts in 2– 3 days • Painful enlarged lymph nodes Objective Data • Inoculation lesion; may be healing • Lymphadenopathy develops in 1–2 weeks in the region that drains the primary lesion. • Single lymph node most often, but multiple nodes are involved occasionally • Tender nodes commonly in head, neck, and axillae; the accessible nodal areas in the arms and legs are less often involved. • Nodes can be very large—up to several centimeters; often red and tender and occasionally suppurate • Diagnosis can be made in the presence of a nodal enlargement lasting longer than 3 weeks, accompanied by an inoculation lesion of the skin and after an interaction with a cat, a cat scratch, or cat lick on a break in the skin. • Lymphadenopathy can last for 2–4 months or even longer Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS) Viral infection that attacks the body’s immune system Pathophysiology • Characterized by the dysfunction of cell-mediated immunity • HIV seropositivity (HIV+): antibodies to HIV present, but sequelae of recurrent infections and neoplastic disease has not yet occurred • AIDS manifested clinically as the development of recurrent, often severe, opportunistic infections • Common life-threatening diseases associated with full-blown AIDS include Kaposi sarcoma, Pneumocystis jiroveci pneumonia, pulmonary tuberculosis, recurrent pneumonia, invasive cervical15 Quiz 3 Study Guide cancer, a parotid enlargement simulating mumps, anemia and thrombocytopenia, chronic diarrhea, and recurrent infections Subjective Data • Enlarged lymph nodes • Initial symptoms include severe fatigue, malaise, weakness, persistent unexplained weight loss, fevers, arthralgias, and persistent diarrhea Objective Data • Generalized lymphadenopathy • In children there may be a prolonged clinical latent period, but initial signs may include neurodevelopmental problems with loss of developmental milestones • Progressive infection characterized by decreasing CD4+ T-lymphocyte count and increasing viral load level Serum Sickness (Type III Hypersensitivity Reaction) An immune complex disease Pathophysiology • Systemic type III hypersensitivity reaction in response to antigens • Mediated by the tissue deposition of circulating immune complexes, the activation of complement, and the ensuing inflammatory response • Patient can react similarly to repeated exposure to the stimuli; subsequent reactions may be more severe and even fatal Subjective Data • Enlarged lymph nodes • Pain, pruritus, and erythematous swelling at the injection site • Urticaria, other rashes, lymphadenopathy, joint pain, fever, and at times facial edema • Medications: beta-lactam antibiotics (especially cefaclor), sulfonamide antibiotics, minocycline • Organ transplant Objective Data • Findings become apparent about 7–10 days after administration of the provoking substance • Urticaria, maculopapular or purpuric lesions • Lymphadenopathy most prominent in the area draining the injection site; can be generalized • Facial and neck edema • Symptoms subside slowly, recurring at times over several weeks Latex Allergy Type IV Dermatitis Delayed hypersensitivity reaction Pathophysiology • T cell–mediated, delayed response • Allergic contact dermatitis that involves the immune system and is caused by the chemicals used in latex products Subjective Data • Exposure to latex products • Rash at area of contact16 Quiz 3 Study Guide Objective Data • Skin reaction usually begins 48–72 hours after contact • Vesicular lesions, erythema localized to area of contact • Reaction may progress to oozing skin blisters Latex Allergy Type I Reaction True allergic reaction caused by protein antibodies Pathophysiology • Immunoglobulin E antibodies form as a result of interaction between a foreign protein and the body’s immune system. • Antigen-antibody reaction causes release of histamine, leukotrienes, prostaglandins, and kinins Subjective Data • Exposure to latex • Allergy to cross-sensitizing foods (e.g., banana, avocado, potato, tomato, kiwi) Objective Data • Local: urticaria (skin wheals) • Systemic: generalized urticaria with angioedema (tissue swelling), asthma, eye/nose itching and gastrointestinal symptoms, anaphylaxis (cardiovascular collapse) Lymph Node Inspection and Palpation 195-197 Disorders of the lymph system present with three possible physical signs: enlarged lymph nodes (lymphadenopathy), red streaks on the overlying skin (lymphangitis), or lymphedema (Box 10.2). Inspect each area of the body for apparent lymph nodes, edema, erythema, red streaks, and skin lesions. Using the pads of the second, third, and fourth fingers, gently palpate for superficial lymph nodes (see Box 10.1 and Fig. 10.14). Try to detect any hidden enlargement, and note the consistency, mobility, tenderness, size, and warmth of the nodes. In areas where the skin is more mobile, move the skin over the area of the nodes. Press lightly at first, then gradually increase pressure. Heavier pressure alone can displace nodes before you have had a chance to recognize their presence. Superficial nodes are accessible to palpation but in healthy adults are not large or firm enough to be felt. You may detect small, movable, discrete, “shotty” nodes (small, multiple nodes that feel like BBs under the skin) less than 1 cm in diameter that move under your fingers. Shotty nodes are generally of no clinical consequence and usually represent transient enlargement of the lymph nodes after viral infection. However, even shotty nodes in the epitrochlear or supraclavicular regions require additional evaluation. A node fixed to surrounding tissues is cause for concern.17 Quiz 3 Study Guide Special Procedures for Assessment of the Musculoskeletal System 22.2 page 560 Knee Assessment 563-565 Ballottement is used to determine the presence of an effusion in the knee from excess fluid. With the knee extended, apply downward pressure on the suprapatellar pouch with the web or the thumb and forefinger of one hand, and then push the patella quickly downward against the femur with a finger of your other hand. If an effusion is present, a tapping or clicking will be sensed when the patella is pushed against the femur. Release the pressure against the patella, but keep your finger lightly touching it. If an effusion is present, the patella will float out as if a fluid wave were pushing it (Fig. 22.47). Examination for the bulge sign is also used to determine the presence of excess fluid in the knee. With the patient’s knee extended, milk the medial aspect of the knee upward two or three times, and then milk the lateral side of the patella. Observe for a bulge of returning fluid to the hollow area medial to the patella (Fig. 22.48). The McMurray test is used to detect a torn medial or lateral meniscus. Have the patient lie supine and flex one knee. Position your thumb and fingers on either side of the joint space. Hold the heel with your other hand, fully flexing the knee, and rotate the foot and knee outward (valgus stress) to a lateral position. Extend and then flex the patient’s knee. Any palpable or audible click, pain, or limited extension of the knee is a positive sign of a torn medial meniscus. Repeat the procedure, rotating the foot and knee inward (varus stress) (Fig. 22.49). A palpable or audible click, pain, or lack of extension is a positive sign of a torn lateral meniscus. The anterior and posterior drawer test is used to identify instability of the anterior and posterior cruciate ligaments. Have the patient lie supine and flex the knee 45 to 90 degrees, placing the foot flat on the table. Place both hands on the lower leg with the thumbs on the ridge of the anterior tibia just distal to the tibial tuberosity. Draw the tibia forward, forcing the tibia to slide forward of the femur. Then push the tibia backward (Fig. 22.50). Anterior or posterior movement of the knee greater than 5 mm in either direction is an unexpected finding.18 Quiz 3 Study Guide The Lachman test is used to evaluate anterior cruciate ligament integrity. With the patient supine, flex the knee 10 to 15 degrees with the heel on the table. Place one hand above the knee to stabilize the femur and place the other hand around the proximal tibia. While stabilizing the femur, pull the tibia anteriorly. Attempt to have the patient relax the hamstring muscles for an optimal test. Increased laxity, greater than 5 mm compared with the uninjured side, indicates injury to the ligament. The varus (abduction) and valgus (adduction) stress tests are used to identify instability in the lateral and medial collateral ligaments. Have the patient lie supine and extend the knee. Stabilize the femur with one hand and hold the ankle with your other hand. Apply varus force against the ankle (toward the midline) and internal rotation. Excessive laxity is felt as joint opening. Laxity in this position indicates injury to the lateral collateral ligament. Then apply valgus force against the ankle (away from the midline) and external rotation. Laxity in this position indicates injury to the medial collateral ligament (Fig. 22.51). Repeat the movements with the patient’s knee flexed to 30 degrees. No excessive medial or lateral movement of the knee is expected. Hand and Wrist assessment p. 560-562 Several procedures are used to evaluate the integrity of the median nerve, which innervates the palm of the hand and the palmar surface of the thumb, index and middle fingers, and half of the ring finger. Ask the patient to mark the specific locations of pain, numbness, and tingling on the Katz hand diagram (Fig. 22.41). Certain patterns of pain, numbness, and tingling are associated with carpal tunnel syndrome. The thumb abduction test isolates the strength of the abductor pollicis brevis muscle, innervated only by the median nerve. Have the patient place the hand palm up and raise the thumb perpendicular to it. Apply downward pressure on the thumb to test muscle strength (Fig. 22.42A). Full resistance to this pressure is expected. Weakness is associated with carpal tunnel syndrome. To perform the Phalen test, ask the patient to hold both wrists in a fully palmar-flexed position with the dorsal surfaces pressed together for 1 minute (Fig. 22.42B). Numbness and paresthesia in the distribution of the median nerve are suggestive of carpal tunnel syndrome. The reverse Phalen test is performed by placing the palms and fingers together with full wrist extension. The Tinel sign is tested by striking the patient’s wrist with your index or middle finger where the median nerve passes under the flexor retinaculum and volar carpal ligament (Fig. 22.42C). A tingling sensation radiating from the wrist to the hand in the distribution of the median nerve is a positive Tinel sign and can indicate carpal tunnel syndrome. Musculoskeletal abnormalities Page 571-577 Ankylosing Spondylitis A chronic inflammatory disease of the spine, ankylosing spondylitis has a genetic predisposition associated with human leukocyte antigen (HLA)-B27 and may affect the cervical, thoracic, and lumbar spine along with the sacroiliac joints (Fig. 22.66) Pathophysiology • Inflamed intervertebral disks and longitudinal ligaments ossification • Leads to eventual fusion and severe deformity of the vertebral column Subjective Data • Develops predominantly in men between 20 and 40 years of age19 Quiz 3 Study Guide • Begins insidiously with inflammatory low back and buttock pain, also involving hips and shoulders • Buttock pain can fluctuate from one side to the other Objective Data • Restriction in the lumbar flexion of the patient • Limited range of motion of the shoulders, chest wall, hips, and knees may develop • Uveitis may be present Lumbosacral Radiculopathy (Herniated Lumbar Disk) Herniation of a lumbar disk that irritates the corresponding spinal nerve root Pathophysiology • Generally caused by degenerative changes of the disk • Most commonly occurring at the L4, L5, and S1 nerve roots • Greatest incidence occurs between 31 and 50 years of age Subjective Data • Can be associated with lifting heavy objects • Common symptoms include low back pain with radiation to the buttocks and posterior thigh or down the leg in the distribution of the dermatome of the nerve root • Pain relief is often achieved by lying down Objective Data • Spasm and tenderness over the paraspinal musculature may be present • Potential difficulty with heel walking (L4 and L5) or toe walking (S1) • Numbness, tingling, or weakness in the involved extremity (Fig. 22.67) Lumbar Stenosis Narrowing of the spinal canal Pathophysiology • Canal narrowing from bone and ligament hypertrophy may lead to entrapment of the spinal cord as it traverses the spinal canal Subjective Data • Pain with walking or standing upright that often seems to originate in the buttocks and may then radiate down the legs • Pain relief may occur with sitting or bending forward • Pain may be worsened by prolonged standing, walking, or hyperextending the back Objective Data • In the early stages, the neurologic examination is frequently normal • With progression, the examination may show lower extremity weakness and sensory loss • A stooped forward gait may be present Carpal Tunnel Syndrome Compression on the median nerve (see Fig. 22.41) Pathophysiology • Compression of the nerve within its flexor tendon sheath due to microtrauma, local edema or inflammation, repetitive motion, or vibration of the hands20 Quiz 3 Study Guide • Associated with rheumatoid arthritis, gout, acromegaly, hypothyroidism, and the hormonal changes of pregnancy Subjective Data • Numbness, burning, and tingling in the hands often occur at night • Can also be elicited by flexion/extension movements of the wrist • Pain may radiate to the arms Objective Data • Weakness of the thumb and flattening of the thenar eminence of the palm • Reproduction of symptoms with provocation of the Tinel and Phalen maneuvers Gout A form of arthritis resulting from chronically elevated serum uric acid Pathophysiology • Monosodium urate crystal deposition in joints and surrounding tissues results in acute inflammatory attacks Subjective Data • Sudden onset of a hot, swollen joint; exquisite pain; limited range of motion • Primarily affects men older than 40 years and women of postmenopausal age • Usually affects the proximal phalanx of the great toe, although the wrists, hands, ankles, and knees may be involved Objective Data • The skin over the swollen joint may be shiny and red or purple • Uric acid crystals may form as tophi under the skin with chronic gout (Fig. 22.68) Temporomandibular Joint Syndrome Painful jaw movement Pathophysiology • Caused by congenital anomalies, malocclusion, trauma, arthritis, and other joint diseases Subjective Data • Unilateral facial pain that usually worsens with joint movement • May be referred to any point on the face or neck Objective Data • Most patients have a muscle spasm, and many have clicking, popping, or crepitus in the affected joint Osteomyelitis An infection in the bone Pathophysiology • Usually results from an open wound or systemic infection • Purulent matter spreads through the cortex of the bone and into the soft tissue • Decreased blood flow to the affected bone may lead to bone necrosis21 Quiz 3 Study Guide Subjective Data • Dull pain develops insidiously at the involved site and progresses over days to weeks • Limp or decreased movement in infants and children Objective Data • Signs of infection include edema, erythema, and warmth at the site • Tenderness to palpation, pain with movement, and signs of inflammation such as fevers Bursitis Inflammation of the bursa Pathophysiology • Due to repetitive movement and excessive pressure on the bursa • Can also be due to infection or gout Subjective Data • Common sites include the shoulder, elbow, hip, and knee, with pain and stiffness surrounding the joint around the inflamed bursa • The pain is usually worse during activity Objective Data • Limitation of motion caused by swelling; pain on movement; point tenderness; and an erythematous, warm site (Fig. 22.69) • Soreness may radiate to tendons at the site Paget Disease of the Bone (Osteitis Deformans) A focal metabolic disorder of the bone Pathophysiology • Appears in persons older than 45 years • Excessive bone resorption and bone formation produce a mosaic pattern of lamellar bone Subjective Data • Vertigo and headache as a result of skull involvement • Progressive deafness from involvement of the ossicles or neural elements may develop Objective Data • Bowed tibias, misshapen pelvis, or prominent skull forehead may be evident • Frequent fractures may occur Osteoarthritis The deterioration of the articular cartilage covering the ends of bone in synovial joints Pathophysiology • As a result of cartilage abrasion, pitting, and thinning, the bone surfaces are eventually exposed, with bone rubbing against bone • Separately there can be remodeling of the bone surface and formation of bone spurs Subjective Data • Pain in hands, feet, hips, knees, and cervical or lumbar spine (most commonly)22 Quiz 3 Study Guide • Onset usually begins after 40 years of age and develops slowly over many years with nearly 100% of people older than 75 years affected Objective Data • The joints may be enlarged due to bone growths (osteophytes) (see Fig. 22.18B) • May have crepitus and limited, painful range of motion Rheumatoid Arthritis A chronic systemic inflammatory disorder of the synovial tissue surrounding the joints Pathophysiology • Cause is unknown • Within the inflamed synovial tissue and fluid, polymorphonuclear leukocytes aggregate • Multiple inflammatory cytokines and enzymes are released that can result in subsequent damage to bone, cartilage, and other tissues Subjective Data • Joint pain and stiffness, especially in the morning or after periods of inactivity • Constitutional symptoms of fatigue, myalgias, weight loss, and low-grade fever are common Objective Data • Involved joints include the hands, wrists, feet, and ankles, as well as the hips, knees, and cervical spine • Synovitis, with soft tissue swelling and effusions, is present on examination • Nodules and characteristic deformities can develop (see Fig. 22.16) Heberden nodes vs Bouchard nodes p 547 Bony overgrowths in the distal interphalangeal joints, which are felt as hard, non-tender nodules usually 2 to 3 mm in diameter but sometimes encompassing the entire joint, are associated with osteoarthritis. When located along the distal interphalangeal joints, they are called Heberden nodes; those along the proximal interphalangeal joints are called Bouchard nodes. Painful swelling of the proximal interphalangeal joints causes spindle-shaped fingers, which are associated with the acute stage of rheumatoid arthritis (Fig. 22.18). Cystic, round, non-tender swellings along tendon sheaths or joint capsules that are more prominent with flexion may indicate ganglia Sports injuries 576-577 Muscle Strain Pathophysiology • Can be due to excessive stretching or forceful contraction beyond the muscle’s functional capacity • Often associated with improper exercise warm-up, fatigue, or previous injury Subjective Data • Muscle pain • Severity ranges from a mild intrafibrous tear to a total rupture of a single muscle Objective Data • Temporary muscle weakness, spasm, pain, and contusion23 Quiz 3 Study Guide Dislocation Complete separation of the contact between two bones in a joint Pathophysiology • Often caused by pressure or force pushing the bone out of the joint; usually occurs in the setting of acute trauma Subjective Data • Can occur more easily in patients with hyperextensibility conditions (e.g., Marfan, Ehlers-Danlos) Objective Data • Deformity and inability to use the extremity or joint as usual Fracture Partial or complete break in the continuity of a bone Pathophysiology • From trauma (direct, indirect, twisting, or crushing) Subjective Data • Pain, limited movement, cannot bear weight, swelling • Felt a pop or snap with injury • Can occur more easily in patients with bone disorders (e.g., osteogenesis imperfecta, osteoporosis, bone metastasis) Objective Data • Deformity, edema, pain, loss of function, color changes, and paresthesia Tenosynovitis (Tendonitis) Inflammation of the synovium-lined sheath around a tendon Pathophysiology • Seen with repetitive actions associated with occupational or sports activities • Can occur in inflammatory conditions like rheumatoid arthritis Subjective Data • Pain with movement of such common sites as the shoulder, knee, heel, and wrist Objective Data • Point tenderness over the involved tendon • Pain with active movement and some limitation of movement in the affected joint Rotator Cuff Tear Microtrauma and tearing of the rotator cuff muscles, most often the supraspinatus Pathophysiology • Usually due to degeneration of the muscle and tendon from repeated overhead lifting and compression under the acromion • An acute tear may also result from a fall on an outstretched arm24 Quiz 3 Study Guide Subjective Data • Pain in the shoulder and deltoid area is common. This can awaken the patient at night Objective Data • Inability to maintain a lateral raised arm against resistance may develop due to pain • Tenderness over the acromioclavicular joint • Grating sound on movement, crepitus, and weakness in external shoulder rotation Infant and Children 577-579 Clubfoot (Talipes Equinovarus) Fixed congenital defect of the ankle and foot Pathophysiology • Causes include genetic factors and external influences in the final trimester, such as intrauterine compression Subjective Data • Diagnosis is usually obvious at birth with the characteristic deformity Objective Data • Most common combination of position deformities includes inversion of the foot at the ankle and plantar flexion, with the toes lower than the heel (Fig. 22.70) Metatarsus Adductus (Metatarsus Varus) The most common congenital foot deformity; can be either fixed or flexible Pathophysiology • Defect is caused by intrauterine positioning • Medial adduction of the toes and forefoot results from angulation at the tarsometatarsal joint Subjective Data • Diagnosis is usually obvious at birth with the characteristic deformity • The heel and ankle are uninvolved (Fig. 22.71) Objective Data • The lateral border of the foot is convex • A crease is sometimes apparent on the medial border of the foot Legg-Calvé-Perthes Disease Avascular necrosis of the femoral head Pathophysiology • Results from a decreased blood supply to the femoral head Subjective Data • Most commonly seen in boys between 3 and 11 years of age • Pain is often referred to the medial thigh, knee, or groin • Bilateral involvement may occur in 10% of cases25 Quiz 3 Study Guide Objective Data • Child may have a limp that is painless or antalgic (painful limp with shortened time on extremity) • Loss of internal rotation; abduction and decreased range of motion on the affected side are seen • Muscle weakness of the upper leg may be present if symptoms have been present for a prolonged period Osgood-Schlatter Disease A traction apophysitis (inflammation of a bony outgrowth) of the anterior aspect of the tibial tubercle Pathophysiology • Inflammation of a bony outgrowth of the anterior aspect of the tibial tubercle • Develops in association with inflammation of the anterior patellar tendon • This self-limiting disorder is most common in boys between 9 and 15 years of age Subjective Data • The child may walk with a limp • Often describes knee pain (especially with activity) Objective Data • Knee swelling that is aggravated by strenuous activity • Pain especially prominent with activity involving the quadriceps muscle • Pain with palpation over the tibial tuberosity Slipped Capital Femoral Epiphysis Disorder in which the capital femoral epiphysis slips over the neck of the femur Pathophysiology • Most common between 8 and 16 years of age, although affected girls are often younger than affected boys • Majority of cases (75%) are unilateral; left side is involved more often than the right • More common in overweight and obese patients Subjective Data • The child or adolescent presents with knee pain and a limp Objective Data • The affected child has leg weakness and reduced internal hip rotation • Characteristic plain radiograph shows slippage of femoral head Muscular Dystrophy A group of genetic disorders involving gradual degeneration of the muscle fibers Pathophysiology • Progressive symmetric weakness and muscle atrophy or pseudohypertrophy from fatty muscle infiltrates • Skeletal muscles and the heart may be involved. • Some forms result in only mild disability, and these patients can expect a normal life span. • Other types produce severe disability, deformity, and death Subjective Data • Early signs may include clumsiness, difficulty climbing stairs, and frequent falls26 Quiz 3 Study Guide Objective Data • Muscle atrophy and weakness with a waddling gait • A positive Gower sign (see Fig. 22.64) • Progressive loss of function, including ability to walk Scoliosis Physical deformity of the spine Pathophysiology • A curvature of the vertebral bodies such that when viewed from the rear, the spine may look more like an “S” or a “C” rather than a straight line • Structural scoliosis most commonly affects girls and progresses during early adolescence. • There is no known cause Subjective Data • May lead to back discomfort and is often associated with a leg length discrepancy Objective Data • Lateral curvature of the spine, rib hump as the child flexes forward to touch the toes • Scoliometer reading of greater than or equal to 7 degrees is a positive screening test • In severe deformities, the patient has uneven shoulder and hip levels; may have a crease on one side at the waist • Physiologic alterations occur in the spine, chest, and pelvis (Fig. 22.72) Radial Head Subluxation (Nursemaid’s Elbow) A dislocation injury Pathophysiology • Caused by jerking the arm upward while the elbow is extended • The jerking pulls apart the elbow joint and tears the margin of the annular ligament around the radial head into the joint • Common in children 1 to 4 years of age Subjective Data • Child complains of pain in the elbow and wrist and/or refuses to move the arm Objective Data • Child holds the arm slightly flexed and pronated • Supination motion is resisted Infants 566-567 Genetic disorders and fetal conditions can produce musculoskeletal anomalies. The fetus may experience various postural pressures leading to reduced extension of the extremities and torsions of various bones. Fully undress the infant and observe the posture and spontaneous generalized movements. Use a warming table when examining a newborn. No localized or generalized muscular twitching is expected. Inspect the lower back for tufts of hair, dimples, discolorations, cysts, or masses near the spine. A mass near the spine is likely to be a meningocele or myelomeningocele.27 Quiz 3 Study Guide From about age 2 months, the infant should be able to lift the head and trunk from the prone position, giving you an indication of forearm strength. Assess the curvature of the spine and the strength of the paravertebral muscles with the infant in a sitting position. Kyphosis of the thoracic and lumbar spine will be apparent in the sitting position until the infant can sit without support (Fig. 22.53). Inspect the extremities, noting symmetric flexion of arms and legs. The axillary, gluteal, femoral, and popliteal creases should be symmetric, and the limbs should move freely. No unusual proportions or asymmetry of limb length or circumference, constricted annular bands, or other deformities should be noted. Place the newborn in a fetal position to observe how that may have contributed to any asymmetry of flexion, position, or shape of the extremities. Newborns have some resistance to full extension of the elbows, hips, and knees. Movements should be symmetric. All infants are flat-footed, and many newborns have a slight varus curvature of the tibias (tibial torsion) or forefoot adduction (metatarsus adductus) from fetal positioning. The midline of the foot may bisect the third and fourth toes rather than the second and third toes. The forefoot should be flexible, straightening with abduction. It is necessary to follow tibial torsion and metatarsus adductus variations carefully, but they seldom require intervention. As growth and development take place, the expected body habitus is usually achieved. The hands should open periodically with the fingers fully extended. Observe the palmar and phalangeal creases on each hand. A single crease extending across the entire palm is frequently associated with Down syndrome and other genetic conditions, but it may also be seen in healthy individuals. Count the fingers and toes, noting polydactyly (six or more digits on an extremity) or syndactyly (two or more digits fused together) (Fig. 22.54). Palpate the clavicles and long bones for fractures, dislocations, crepitus, masses, and tenderness. One of the most easily missed findings in the newborn is a fractured clavicle. This may be evident by a lump on the collarbone caused by the callus that forms on the healing clavicle noted in the first weeks after birth. Position the baby with the trunk flexed and palpate each spinal process. Feel the shape of each, noting whether it is thin and well-formed, as expected, or whether it is split, possibly indicating a bifid defect (Fig. 22.55). Range of Motion and Muscle tone p. 547 Examine both the active and passive range of motion for each major joint and its related muscle groups. Muscle tone is often evaluated simultaneously. Allow adequate space for the patient to move each muscle group and joint through its full range. Instruct the patient to move each joint through its range of motion as detailed in specific joint and muscle sections. Pain, limitation of motion, spastic movement, joint instability, deformity, or contracture may suggest a problem with the joint, related muscle group, or nerve supply. Ask the patient to relax and allow you to passively move the same joints until the end of the range of motion is felt. Do not force the joint if there is pain or muscle spasm. Muscle tone may be assessed by feeling the resistance to passive stretch. During passive range of motion, the muscles should have slight tension. Passive range of motion often exceeds active range of motion by 5 degrees. The28 Quiz 3 Study Guide range of motion with active and passive maneuvers should be equal between contralateral joints. Discrepancies between active and passive ranges of motion may indicate true muscle weakness or a joint disorder. No crepitation or tenderness with movement should be apparent. Note the specific location of tenderness when present. Spastic muscles are harder to put through the range of motion. Measurements may vary if the muscle tested relaxes with gentle persistence. When a joint appears to have an increase or limitation in its range of motion, a goniometer (see Chapter 3) can be used to precisely measure the angle. Begin with the joint in the fully extended or neutral position, and then flex the joint as far as possible. Measure the angles of greatest flexion and extension, comparing these with the expected joint flexion and extension values (Fig. 22.13). Evaluating the strength of each muscle group is an important part of the neurologic examination. However, it is usually integrated with the examination of the associated joint for range of motion. Ask the patient first to contract the muscle you indicate by extending or flexing the joint and then to resist as you apply force against that muscle contraction (Fig. 22.14). Alternatively, tell the patient to push against your hand to feel the resistance. Compare the muscle strength bilaterally. Expect muscle strength to be bilaterally symmetric with full resistance to opposition. Full muscle strength requires a complete active range of motion. Variations in muscle strength are graded from no voluntary contraction to full muscle strength, using the scale in Table 22.1. When muscle strength is grade 3 or less, disability is present; activity cannot be accomplished in a gravity field, and external support is necessary to perform movements. Weakness may result from an underlying muscle disorder, pain, fatigue, or overstretching.