DERMATOLOGY - BOARD REVIEW QUESTIONS AND ANSWERS 2024.

Alopecia Areata Nonscarring immune mediated hair loss Scalp MC Commonly associated with other autoimmune disorders *** like thyroid, addison's disease S/S- smooth discrete circular patches of complete hair loss Exclamation point hairs * - short hairs broken off a few mm from the scalp at the margins of the patches with tapering near the proximal hair shaft Tx- Local- intralesional steroids Extensive- topical steroids Androgenetic Alopecia Loss of hair associated with Dihydrotestosterone (DHT) Tx- Minoxidil- best used if recent onset alopecia involving a smaller area Oral Finasteride- 5 alpha reductase inhibitor, inhibits the conversion of testosterone to dihydrotestosterone S/E- decreased libido, sexual dysfunction Atopic dermatitis Atopic triad- eczema, allergic rhinitis, and asthma Pathophys- T cell mediated immune reaction to a certain trigger and increased IgE production S/S- PRURITIS!!! Acute lesions- erythematous, ill-defined blisters/papules/plaques that later dries and crusts over with scales; MC in flexor creases; + Dermatographism- localized development of hives when skin is stroked Nummular eczema- sharply defined coin-shaped lesions especially on the dorsum of the hands, feet, and elbows/knees Tx- topical corticosteroids and antihistamines for itching, wet dressings, maintain skin hydration with Eucerin or Aquaphor, avoid frequent baths Contact dermatitis Includes diaper rash Burning, itching, and erythema to the area Tx- avoid irritants, wet dressings, topical steroids Diaper rash- frequent diaper changes, topical petroleum jelly or zinc oxide Dyshidrosis Triggers- sweating, stress, warm weather, metals S/S- pruritic "TAPIOCA-LIKE" tense vessicles on the soles, palms, and fingers Tx- topical steroids, ointments preferred Lichen Simplex Chronicus Skin thickening seen in patients with eczema secondary to repetitive rubbing and scratching S/S- scaly, well demarcated, rough hyperkeratotic plaques with exaggerated skin lines Tx- avoid scratching and topical high-strength steroids Perioral dermatitis Papulopustules on an erythematous base, may become confluent into plaques with scales May have satellite lesions Spares vermillion border Tx- Topical- Metronidazole or Erythromycin!! Oral- Tetracyclines AVOID TOPICAL CORTICOSTEROIDS! That is probably what caused the problem! Lichen Planus idiopathic cell mediated immune response Increased incidence with hepatitis C *** 5 P's- Purple, Polygonal, Planar, Pruritic Papules with fine scales and irregular borders MC on flexor surfaces and on the skin, mouth, scalp, genitals, and nails + Koebner's phenomenon ** - new lesions at sites of trauma (also seen with psoriasis) + Wickham striae ** - fine white lines on the skin lesions or on the oral mucosa Tx- topical corticosteroids are 1st line with antihistamines for itching and occlusive dressings The rash will resolve on its own in 8-12 months without treatment Lichen planus in mouth Lichen planus picture Pityriasis Rosea Uncertain etiology, may have link to viral infections Seen in older children and young adults Can mimic syphilis so check RPR if sexually active *** Herald patch seen first (solitary salmon colored macule) on the trunk and 2-6 cm in diameter followed by a smaller, very pruritic 1 cm oval salmon-colored papules with white circular COLLARETTE scaling along the cleavage lines ** Christmas tree pattern Confined to trunk and extremities Tx- NONE PO antihistamines for itchiness, oatmeal baths, may give topical corticosteroids Psoriasis chronic, multisystemic inflammatory immune disorder with genetic predisposition Pathophys- Keritin hyperplasia (proliferating cells at the stratum basale + stratum spinosum due to T cell activation which leads to greater epidermal thickness) S/S- PLAQUE MC type- raised, dark red papules/plaques with THICK SILVER/WHITE SCALES ** MC on extensor surfaces of the elbows and knees, scalp, nape of the neck Nail pitting may be present Usually itchy Yellow-brown discoloration under the nail- OIL SPOT, pathognomonic ************** + Auspitz sign- punctate bleeding with removal of a plaque or scale, not specific (also seen with actinic keratosis) + Koebner's phenomenon- new skin lesions at site of traume (also seen with eczema) PUSTULAR- deep, yellow non-infected pustules that evolve into red macules on the palms/soles GUTTATE- small, erythematous papules with fine scales and discrete lesions INVERSE- lacks a scale, erythematous Erythrodermic generalized erythematous rash on most of the skin and the worst type Psoriatic arthritis- inflammatory arthritis associated with psoriasis; "sausage digits"; joint stiffness for > 30 minutes and relieved with activity, "pencil in cup" deformity on x-ray Tx- Mild-Mod = topical steroids + vitamin D analogs (Calcipotriene) Mod-Severe = phototherapy: UVB, Methotrexate Pityriasis (tinea) Versicolor Overgrowth of the yeast Malassezia furfur- part of the normal skin flora S/S- hyper/hypopigmented well-demarcated round/oval macules with fine scaling; they often coalesce into patches on the trunk, face, and extremities; the involved skin fails to tan with sun exposure Dx- KOH prep= hyphae and spores "spaghetti and meatball" appearance Wood's lamp= yellow, green flourescence Tx- topical antifungals like Selenium sulfide, Sodium sulfaccetamide, Zinc pyrithione, "azoles" Systemic therapy- Itraconazole or Fluconazole, but must not shower for 8-12 hours after because they are delivered to the skin via sweat