USMLE Final Exam Questions and Answers Latest Updated 2024 (Graded A+)

USMLE Final Exam Questions and Answers Latest Updated 2024 (Graded A+) Pseudogout associations - ANSWER-hemochromatosis, hyperparathyroidism, acromegaly, hypothyroidism Gout crystals - ANSWER-negatively birefringent needles Pseudogout crystals - ANSWER-positively birefringent needles Vasculitis associated with chronic Hep B - ANSWER-polyarteritis nodosa Vasculitis associated with chronic Hep C - ANSWER-cryoglobulinemia Best blood test for polyarteritis nodosa - ANSWER-There is none. Get abdominal angiography first, then biopsy of muscle, skin, or sural nerve. Churg-Strauss - ANSWER-vasculitis + eosinophilia + asthma Takayasu's arteritis - ANSWER-young asian female with diminished pulses (usually preceeded by fatigue, weight loss, arthralgia, anemia, elevated ESR) Best test for Takayasu's - ANSWER-aortic angiography or MRA Bite cells on blood smear - ANSWER-G6PD Burr/Spur cells on blood smear - ANSWER-liver disease Acanthocytes on blood smear (looks like spur cell but with more rounded spurs) - ANSWER-liver disease, hypothyroidism, alcoholism Basophilic stippling on blood smear - ANSWER-lead poisoning Schistocytes on blood smear - ANSWER-TTP-HUS, DIC, prosthetic heart valve, malignant htn, sepsis Target cells on blood smear - ANSWER-thalassemia, other hemoglobinopathies, liver disease 5 causes of microcytic anemia - ANSWER-iron deficiency, lead poisoning, anemia of chronic disease (but usually normocytic), thalassemia, sideroblastic anemia (can also have high MCV) Antibody test for celiac disease - ANSWER-anti-endomysial, tissue transglutaminase (small bowel bx is best though) Antibiotics for MRSA - ANSWER-IV: vanc, linezolid, daptomycin, tigecycline; if minor infection, can use oral: TMP/SMX, doxy, minocycline, or maybe clindamycin (there is inducible resistance to clinda though) Antibiotics for MSSA - ANSWER-Oxacillin/nafcillin, dicloxacillin (IV and oral), cefazolin (IV), cephalexin (oral) Can you use cephalosporins in pt allergic to PCN? - ANSWER-yes, if the rxn is rash only; no if pt has true anaphylaxis Antibiotics to use for Staph with PCN allergy - ANSWER-cephalosporins if rash only; macrolides, clindamycin, vancomycin, linezolid, daptomycin, TMP/SMX Antibiotics for strep - ANSWER-PCN, ampicillin, amoxicillin Antibiotics for GNRs - ANSWER-Cephalosporins: cefepime, ceftazidime PCNs: piperacillin, ticaricillin Monobactam: Aztreonam Quinolones: cipro, levo, gati, moxi Aminoglycs: gentamicin, tobramycin, amikacin Carbapenems: imipenem, mero, erta Limitation of ertapenem - ANSWER-does NOT cover pseudomonas Piperacillin and ticarcillin - ANSWER-GNRs strep anaerobes Carbapenems - ANSWER-good anaerobic coverage strep MSSA Tigecycline - ANSWER-MRSA good GNR coverage Anaerobes - ANSWER--metronidazole is BEST for abdominal anaerobes (carbapenems, piperacillin, and ticarcillin have equal efficacy) -cefoxitin and cefotetan are the ONLY cephalosporins -respiratory anaerobes: clindamycin Abx with NO anaerobic coverage - ANSWER-aminoglycs, aztreonam, fluoroquinolones, oxacillin/nafcillin, all cephalosporins EXCEPT cefoxitin and cefotetan Red man syndrome - ANSWER-red, flushed skin from histamine release, associated with rapid infusion of vancomycin (so slow down the infusion rate) Osteomyelitis - ANSWER--most common is staph: oxacillin or nafcillin IV for 4-6 wks for MSSA; vanc, linezolid or dapto for MRSA -GNRs: salmonella or pseudomonas, can use orals, but must cx org. first and make sure it is sensitive (BONE bx and cx) Cellulitis tx - ANSWER--minor infection: oral dicloxacillin or cephalexin -severe: IV oxacillin, nafcillin or cefazolin -PCN allergy: if rash, then cephalosporin; if anaphylaxis, then vanc, linezolid, dapto (macrolides or clinda for minor infection) Sequelae of strep infection - ANSWER--throat: rheumatic fever AND glomerulonephritis -skin: ONLY glomerulonephritis Gonorrhea tx - ANSWER--ceftriaxone IM -cefixime oral -cefpodoxime oral -ciprofloxacin oral (2d line) -if pregnant, then ceftriaxone IM -ALSO treat for chlamydia Chlamydia tx - ANSWER--azithromycin (single dose) -doxycycline (for 1 wk) -if pregnant, then azithro -ALSO treat for gonorrhea Recurrent gonorrhea associated with... - ANSWER-terminal complement deficiency (predisposes to any Neisseria infection) PID tx - ANSWER--outpatient: ceftriaxone (IM) and oral doxy -inpatient: cefoxitin or cefotetan IV + doxy + (maybe) metronidazole Abx safe in pregnancy - ANSWER--PCNs -cephalosporins -aztreonam -erythromycin -azithromycin Epidydimo-orchitis tx - ANSWER--if 35 yo, then ceftriaxone + doxy -if 35 yo, then fluoroquinolone Chancroid - ANSWER--PAINFUL ulcer caused by Hemophilus ducreyi -swab for gram stain and culture (on Nairobi medium or Mueller-Hinton agar) -treat with ceftriaxone IM or single dose azithromycin What treats MRSA and VRE? - ANSWER-daptomycin What binds toxin in gas gangrene? - ANSWER-clindamycin Common bugs in dog bite - ANSWER-Capnocytophaga canimorsus (GNR) most common, Pasteurella multocida may be present in 25%, anaerobes Bug that causes overwhelming sepsis in asplenics with dog bite - ANSWERCapnocytophaga canimorsus Typical bugs in cat bite - ANSWER-Pastuerella multocida, anaerobes Typical bugs in reptile bite - ANSWER-Salmonella, Pseudomonas (snakes) Treatment for animal bite - ANSWER-Amox/clavulanate PCN allergy: doxy OR TMP/SMX OR fluoroquinolone PLUS clinda for anaerobes Severe infxn: use IV (like unasyn) Duration: 3-5 days for prophy, 7-14 days for infection Typical bugs in human bites - ANSWER-Eikenella corrodens, streptococci, staphylococci, Haemophilus species, and a multitude of anaerobes Treatment for human bite - ANSWER-Same as animal bite but be careful tendons or bones not involved if clenched fist Common bugs in diabetic foot ulcer - ANSWER-staphylococci, streptococci, enteric gram-negative rods, P. aeruginosa, and anaerobes Treatment of diabetic foot ulcer - ANSWER-Broad until cx results known (if severe infection): must cover GPC, GNR, and anaerobes, eg vanc + mero If mild, cover for staph and strep Aeromonas hydrophila - ANSWER-This gram-negative bacterium is found in freshwater environments, although it may also be present in brackish water. Infections are more likely to occur during warmer weather. Soft tissue involvement and bacteremia/sepsis can develop in patients with underlying immunocompromising diseases, including cirrhosis and cancer. The clinical presentations of infection with Vibrio vulnificus and Aeromonas species can be quite similar. This organism is often susceptible to fluoroquinolones, trimethoprim-sulfamethoxazole, tetracyclines, imipenem, aminoglycosides, and third- or fourth-generation cephalosporins Treatment for necrotizing fasciitis - ANSWER--need to cover MRSA, GABHS, GNRs, anaerobes -vanc AND: pip/tazo OR cefepime + metronidazole OR meropenem PLUS clinda -MUST add clinda if GABHS is suspected b/c it helps stop toxin production and it is effective even when bacteria are in stationary phase -ALSO need surgical tissue samples for culture in order to narrow abx coverage Treatment of toxic shock syndrome - ANSWER--B lactam abx (PCNs, cephs, carbapenems) -AND clinda (important b/c b-lactams alone can cause INCREASED toxin production) -IVIG effective in strep TSS (in 1 study) but not proven in staph TSS Rocky Mountain Spotted Fever - ANSWER--caused by Rickettsia rickettsii -rash, fever, headache, GI sx, myalgia -rash is initially erythematous maculopapular and progresses to petechial, begins on wrists, ankles, palms and soles before spreading centripetally Vibrio vulnificus - ANSWER--GNR -causes nec fas and sepsis, particularly in liver disease or immunosuppressed pts -hemorrhagic bullae -exposure to warm sea or brackish water (Gulf of Mexico), seafood drippings, consumption of raw seafood like oysters CAP labs - ANSWER--blood cx -sputum cx -influenza A&B rapid antigen test -Legionella and strep pneumo urine antigen test