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USMLE2 Medicine 14
Infectious Disease 03
Question | Answer |
---|---|
Tx of uncomplicated cystitis | 3d TMP/SMX |
Tx of uncomplicated cystitis in DM | 7d TMP/SMX |
If cystitis in pregnancy, what drug do you not use? | flouroquinolones |
pts with pyelo who are immunosuppressed or have indwelling catheters -- what org caused the pyelo? | Candida |
Tx of pyelo | 2 weeks of cipro |
how to tx pregnant pt who has pyelo | admit them |
pt with presentation of pyelo but doesn't get better with tx | consider perinephric abscess |
how to tx perinephric abscess | Abx (CTX) and drainage |
If suspect pernephric abscess, how to dx? | Initial test is U/S, then CT or MRI. Then need aspiration to get bacterial sensitivity. |
Layers of skin | layers CLoGS B skin: stratum Corneum, stratum Lucidum, stratum Granulosum, stratum Spinosum, stratum Basale. |
child with pustular skin infection on arms, legs, face with oozing, crusting (golden yellow), and draining lesions - what is the disease and what is it caused by? | impetigo by GAS or Staph aureus (called bullous impetigo if S aureus) |
How to tx impetigo - mild and serious cases, PCN allergic? | mild - topical bacitracin. Severe - oral keflex or oxacillin (cover GAS and S aureus). PCN allergic use azithromycin |
pt with BL shiny red, indurated edematous tender lesions on face, arms, legs, sharply demarcated from surrounding skin. | erysipelas (superficial cellulitis), caused by GAS. |
How to tx erysipelas? | If sure it's strep, use PCN. If not sure if erysipelas or cellulitis, use oxacillin to cover Staph. |
Tx of tinea corporis/unguium (nails)/capitis | oral itraconazole or terbinafine |
Tx of tinea pedis/cruris | topical clotrimazole or ketoconazole |
How to tx systemic Candidal infection? | amphotericin, fluconazole if less serious |
How to tx Candida paronychia? | (swelling around the nails) amphotericin |
Spaghetti and meatballs under microscope | hyphae and spores of malassezia furfur (pityrosporum orbiculare) |
tan brown white scaling macular lesions that coalesce and don't tan (chest/abd/face) | tinea versicolor - malassezia furfur (pityrosporum orbiculare) |
How to tx tinea versicolor? | Topical Selenium sulfide, clotrimazole, or ketoconazole. If lots of surface area affected, can use oral tx. |
pruritis on flexor surfaces of wrists and finger webs | Scabies (sarcoptes scabiei) |
Scabies is associated with what type of pts? | Down Syndrome |
How to dx scabies? | show parasite in skin scrapings! Ewww! |
Tx for scabies | permethrin |
Tx for lice | permethrin |
Tx for Norwegian scabies | a version of scabies that affects immunocompromised pts with crusting and malodorous discharge. Use permethrin and ivermectin |
skin colored waxy umbilicated papules | molluscum contagiosum, poxvirus |
how to tx molluscum contagiosum | freezing/curettage |
osteomyelitis in children - where and what org? | long bones - femur and tibia, S. aureus |
osteomyelitis in adults - where and what org? | vertebral bodies (lumbar) --> epidural abscess, S. aureus |
risk factor for vertebral osteomyelitis | IVDU |
osteomyelitis in someone with prosthetic joint - what org? | S. aureus |
osteomyelitis in DM - where and what org? | small bones of the lower extremity (repeated trauma), S. aureus |
Best test for osteomyelitis | MRI or technetium bone scan early on, but then definitive is the bone bx |
how to tx acute hematogenous osteo in children? In adults? | in children, abx (oxacillin OR [vanc if MRSA + CTX]) only; in adults, abx with drainage and debridement |
how to tx chronic osteomyelitis? | oxacillin or [vanc if MRSA + CTX], depending on sensitivities, for 12 weeks |
Septic arthritis - what organisms? | Gonorrhea --> S. aureus --> Strep |
Difference between gonoccocal and non-gonoccocal septic arthritis | Gonococcal is polyarticular mostly with petechiae or purpura and nongonococcal is monoarticular |
How to dx Gonococcal vs. Non-gonococcal septic arthritis? | Gonococcal culture cervix/pharynx/rectum/urethra. Nongonococcal culture the synovial fluid. |
How to tx septic arthritis? | joint aspiration and abx with CTX if gonococcal or oxacillin + CTX if non-gonococcal |
soldier in Iraq with shrapnel injury and wound with brownish sweet-smelling discharge | gas gangrene, C. perfringens |
How to tx gas gangrene? | high dose PCN or clindamycin PLUS debridement or amputation |
most common org causing infective endocarditis | S. aureus |
manifestations of infective endocarditis | Jane Osler Roth has a splinter in her pet. Janeway lesions painless, Osler nodes painful, Roth spots on retina, and petechiae |
How to dx infective endocarditis? | 2 MAJOR criteria: blood cx, echo (TEE) or 1 major and 3 minor. MINOR: fever, cardiac lesion, vascular phenomena, immuno phenoma, micro evidence. |
Empiric of infective endocarditis | vancomycin and gentamicin for native valve and IVDU; vanc, gent, and rifampin for prosthetic valves |
In what circumstance would you prophylax for bacterial endocarditis? | only with dental procedures - amoxicillin or clinda for PCN allergic |
pulsus paradoxus | cardiac tamponade |
tx of viral pericarditis | anti-inflammatory - indomethacin --> prednisone if no response |
Tx for TB pericarditis | TB meds and steroids |
myocarditis - most common org | coxsackie |
EKG for myocarditis | nonspecific STT changes |
facial palsy | Lyme |
dx of PCP PNA | CXR, LDH, BAL |
Tx for PCP PNA | TMP/SMX. If severe (PO2<70 or A-a grad >35) then add steroids. |
Prophylaxis for PCP PNA. When to start and stop prophylaxis? | TMP/SMX. Start when CD4<200, stop when CD4>200 >6mo |
Retinitis or esophagitis in HIV pt with shallow ulcers in distal esophagus. What is the CD4 count? | CMV CD4<50 |
Tx of CMV in HIV+ pt | Valganciclovir - retinitis and GI. Ganciclovir --> foscarnet for CNS infection. |
Prophylaxis for CMV in HIV+ pt | Valganciclovir |
Tx of Mycobacteria avium in HIV+ pt | Clarithromycin and ethambutol +/- rifabutin |
Prophylaxis for Mycobacteria avium in HIV+ pt. When to stop prophylaxis? | Azithromycin qweek. Stop when CD4>100 for a few months |
ring enhancing lesion on contrast head CT | toxoplasmosis CD4<100 |
Tx for toxoplasmosis in HIV+ pt | pyrimethamine and sulfadiazine (sulfa allergic then clinda). Also add leucovorin to prevent bone marrow suppression |
Prophylaxis for toxoplasmosis in HIV+ pt | TMP/SMX |
Vaccinations for HIV+ pt | PIB Pneumococcus, influenza, hepatitis B |
AIDS illness for CD4 <50 | CMV, MAI, PML, CNS lymphoma |
AIDS illness for CD4 <100 | Toxoplasmosis, Herpes - disseminated, Cryptosporidiosis, Cryptococcus |
AIDS illness for CD4 <100-200 | PCP, Histo, Cocci, Dementia |
AIDS illness for CD4 <200-500 | thrush, Kaposi, TB, Zoster |
How to know if HIV+ pt has adequate response to antiretrovial tx? | goal is complete suppression of viremia with <50 to 70 copies of HIV-RNA; adequate response when drop of at least 50% of viral load in first month |
When to start AIDS therapy | when CD4 <350 or viral load >55K |
What drugs to start in AIDS tx | 2 nucleoside reverse transcriptase inhibitors (tenofovir/emtricitabine OR AZT/Lamivudine) and one or two protease inhibitors (Ritonavir plus another -navir) |
"boosted protease inhibitors" | give protease inhibitor in combination with ritonavir --> synergystic, decreases the metab of the other PI and enables higher drug levels and increases chances of success |
What to know about Efavirenz | a non-nucleoside reverse transcriptase inhibitor, part of the single HAART pill, only antiretroviral that is contraindicated in pregnancy |
When should HIV+ pregnant woman plan for a C-section? | when viral load >1K |
If HIV+ pregnant pt is not on treatment for her own disease, when should she start antiretroviral treatment for the pregnancy? | 14 weeks of pregnancy |
Post exposure prophy for needlestick from HIV+ | AZT + lamivudine + nelfinavir (PI) for 4 weeks |
undercooked meat (pork/lamb) | Toxoplasmosis |
Tx Q fever | doxy |
Tx for RMSF | doxy |
halo sign around nodular lesion on CXR or chest CT | Aspergillus |
Tx for aspergillus | Voriconazole |