Infectious Disease Flashcards
Potential complication of retropharyngeal abscess
Acute necrotizing mediastinitis (spread through “danger space” through the alar fascia)
X-ray findings in epiglottitis and retropharyngeal abscess.
Epiglottitis: Thumbprint sign
Retropharyngeal abscess: Widened prevertebral space (may be unable to extend neck)
Treatment for tinea capitis
Oral griseofulvin or terbinafine
Treatment for tinea corporis
Topical clotrimazole or terbinafine (if widespread, treat with oral griseofulvin or terbinafine)
Most common predisposing factor for orbital cellulitis
Bacterial sinusitis
Treatment for rhino-orbital-cerebral mucormycosis
Surgical debridement + Ampho B
Who gets oseltimivir for flu?
Over 65, pregnant, chronic illness (prevent complications), or <48 hours since symptom onset (shorten duration)
Additional empiric treatment for aspiration pneumonia
Include anaerobe covereage with amoxicillin-clavulunate, clindamycin, or amoxicillin+metronidazole
Empiric treatment of CAP
No comorbidities or recent antibioticx: Doxycycline or azithromycine
If so: Add ceftriazone or just use respiratory quinolone
Treatment of Legionella
Respiratory quinolones (Levofloxacin for Legionella) or macrolides (e.g. azithromycin)
Immunocompromised person with CT showing pulmonary nodules with surrounding ground-glass opacities
“Halo sign” seen in invasive aspergillosis
Fungal lung disease with ulcerated skin lesions and lytic bone lesions in immunocompetent hosts
Blastomycosis (Wisconsin)
Fungal lung disease in the midwest with hilar lymphadenopathy, arthralgias, and erythema nodosum
Histoplasmosis
Treatment for histoplasmosis
Ampho B in severe disease
Otherwise itraconazole or voriconazole
Fungal lung disease in the southwest with arthralgias, erythema nodosum, and/or erythema multiforme
“Valley fever” due to Coccidioides
Treatment of penicillin-allergic syphilis patients
Primary, secondary, latent: Doxycycline
Tertiary without neurosyphilis: Ceftriaxone
Neurosyphilis: Penicillin desensitization
Sensitivity of testing for primary syphilis
RPR/VDRL have high false negatives. FTA-ABS much more sensitive (>97%)
Disseminated gonorrhea
- Septic monoarthritis
and/or - Migratory polyarthralgias, tenosynovitis, dermatitis (papules and pustules)
Malabsorption with migratory arthritis and low-grade fever
Whipple’s disease - PAS-positive macrophages
Treatment of Giardia
Metronidazole
What medication other than antibiotics carries a risk of C. diff colitis?
PPIs
Filamentous gram positive anaerobic rods with sulfur granules. Organism and treatment?
Actinomyces, treat with penicillin (even though an anaerobe)
Causes cervicofacial infections after dental surgery or trauma
Filamentous gram positive aerobic rods that stain weakly acid-fast. Organism and treatment?
Nocardia, treat with TMP-SMX (for 6-12 mo)
Can cause respiratory infections
Itchy butt and scotch tape test. Organism and treatment?
Enterobius vermicularis, treat with albendazole (or pyrantel pamoate) for patient and household contacts
Myositis, periorbital edema, and eosinophilia. Organism?
Trichinellosis.
Asymptomatic, afebrile liver cyst unless huge or ruptures. Organism? Treatment? Imaging appearance?
Organism: Echinococcus granulosus (dog tapeworm)
Treatment: albendazole
Imaging: Internal septations (daughter cysts) in US, “eggshell” calcifications on CT
Febrile liver cyst with RUQ pain. Organism? Treatment? Imaging appearance?
Organism: Entamoeba histolytica
Treatment: Metronidazole and intraluminal antibiotic (e.g paramomycin)
Imaging: Single subcapsular cyst
Empiric treatment for cat bites? What organism do you need to be sure to cover?
Amoxicillin-clavulunate. Watch for Pasteurella multocida
Treatment for tick-borne diseases: babesiosis, ehrlichiosis, lyme, and RMSF
Babesiosis: Atovaquone + azithromycin (typical) or quinine + clindamycin (severe)
Others: doxycycline
Cells infected by RMSF
Endothelial cells (leads to vasculitis-like illness)
Cells infected by Ehlichiosis
WBCs
UTI with alkaline urine. Possible organism?
Proteus mirabilis
Morbilliform rash after patient with pharyngitis takes amoxicillin
EBV (not true allergy)
Infections associated with cold-agglutin AIHA
EBV, HIV, and Mycoplasma pneumonia
What infections are solid organ transplant patients especially at risk for?
Prophylaxis?
PCP pneumonia and invasive CMV
Prophylaxis with TMP-SMX and valganciclovir
Acute airway obstruction during a febrile infection. Cause? Treatment?
Rare complication of EBV. Give steroids.
Infection associated with focal GI dilatation and heart disease
Chagas disease due to Trypanosoma cruzi.
(GI dilatation: megaesophagus or megacolon)
(Heart: cardiomegaly, CHF, arrhythmias)
Infection associated with high fever, diffuse lymphadenopathy, maculpapular rash, severe polyarthralgias, lymphopenia and thrombocytopenia
Chikungunya fever
Leprosy treatment
Dapsone and rifampin (also clofazimine in severe disease)
CI to yellow fever vaccine
Immune compromise (live attenuated vaccine)
What do you need to test for before diagnosing ITP when isolated thrombocytopenia is seen?
HIV and HCV
CSF finding in primary CNS lymphoma
EBV DNA
Solitary weakly ring-enhancing periventricular brain mass in an AIDS patient
Primary CNS lymphoma
White matter lesions with no edema or enhancement in an AIDS patient
PML
Treatment for cryptococcal meningitis
2 weeks ampho B + flucytosine
Then consolidation/maintenance with fluconazole
Empiric treatment of bacterial meningitis in adults <50?
Over 50?
Immunocompromised?
<50: Vanc + 3rd-gen cephalosporin (ceftriaxone or cefotaxime)
>50: Add ampicillin (Listeria)
Immunocompromised: Vanc + cefepime (Pseudomonas), + ampicillin
Organism behind the chronic diarrhea, plus the CD4 range for each: Watery, no fever Watery, low-grade fever Watery, high fever Bloody
Watery, no fever: Micro/Isosporidium, CD4 < 100
Watery, low-grade fever: Cryptosporidium,CD4 < 180
Watery, high fever: MAC, CD4 < 50
Bloody: CMV, CD4 <50
AIDS patient with painless blurred vision and fundoscopy showing hemorrhages surrounded by yellow-white fluffy lesions.
CMV retinitis
AIDS patient with painful vision changes with fundoscopy showing central retinal necrosis with peripheral pallor
HSV or VZV retinitis (usually associated with keratitis and uveitis as well)
Major toxicities of aminoglycosides (e.g. gentamicin and amikacin)
- Ototoxicity
- Vestibulopathy (no vertigo since symmetric, but has oscillopsia (sensation of objects moving in visual field), abnormal head thrust)
- Nephrotoxicity (AKI due to intrinsic kidney damage)
Electrolyte abnormalities due to TMP-SMX
- Hyperkalemia (blocks ENaC, like the K-sparing diuretic amiloride)
- Elevated creatinine due to competitive inhibition of creatinine secretion (not decreased GFR)
Empiric treatment for fight bite
Amoxicillin-clavulanate
Delayed (1-2 weeks) antibiotic reaction with fever, rash, polyarthralgia, and lymphadenopathy.
Name? Associated antibiotics?
Serum sickness-like reaction
Caused by TMP-SMX and beta-lactams
