Infectious Disease Flashcards
What two organ systems does cryptococcus most commonly affect?
- CNS
2. Lungs
How is cryptococcus treated?
CNS is treated with amphotericin B, followed by fluconazole. Lung involvement is treated with fluconazole.
What findings are seen on chest x-ray in histoplasmosis?
Hilar or mediastinal lymphadenopathy with focal infiltrates. Don’t confuse this with sarcoidosis!
When is pneumocystis jirovecii usually diagnosed?
In aids patients with a CD4 count
What chest x-ray finding is usually seen in pneumocytis?
Bilateral interstitial infiltrates.
What infection leads to rheumatic fever?
Group A strep pharyngitis. Group A strep from skin infection will not lead to rheumatic fever.
What is the treatment of choice for rheumatic fever?
Penicillin. If allergic, give a cephalosporin. If severe allergy is present, give a macrolide or clindamycin.
Why should raw honey never be given to infants?
Increased risk of botulism.
How do patients with botulism classically present?
Classically, they will present with descending weakness/paralysis. This is in contrast to GBS, which present with ascending weakness/paralysis.
Patient recently came back from a trip to mexico and has been having profuse watery diarrhea characterized as rice water stool. What is the most likely diagnosis?
This is the classic presentation for cholera.
How is the diagnosis of active tuberculosis made?
Patients are diagnosed with acid fast bacilli smear and sputum culture collected over 3 consecutive days.
What is the treatment of choice for tuberculosis?
Start with RIPE for two months: R-ifampin I-soniazid P-yrazinamide E- thambutol After two months, discontinue pyrazinamide and ethambutol. Treat for 6 months.
When is PPD done?
Is done in asymptomatic patients only. This is a screening test and should not be used for diagnosis.
What should always be given with isoniazid? Why?
Vitamin B6 (pyridoxine) to prevent peripheral neuropathy.
HIV patient has a head CT scan showing multiple ring enhancing lesions. What is
the next best step in management?
Empiric treatment with:
1. pyrimethamine and sulfadiazine
or
2. clindamycin
When is prophylaxis indicated for lyme disease?
Prophylaxis indicated when:
- Deer tick identified
- Attached >36 hours
- Doxycyline can be given within 72 hours
- Lives in endemic area
- Does not have contraindication to doxycycline
What is the treatment of choice for lyme disease?
8 give doxycycline
Describe the rash seen in rocky mountain spotted fever.
Patients will classically present with a rash that starts at the ankles and wrists and moves centrally. The palms and soles are commonly affected.
What is Jarisch-Herxheimer reaction?
This occurs during penicillin treatment for syphilis. Fever, myalgia, and headache occurs within the first 24 hours of treatment.
When evaluating EBV mononucleosis, a heterophil test is ordered. The test is negative. What is the next lab that should be ordered?
The next test is EBV specific antibodies.
When should the Zoster vaccine be given?
It is recommended in patients >60 years of age. Be aware that it is FDA approved in patients >50 years of age.
What is the main purpose for treating herpes zoster with antivirals?
The main reason is to reduce the incidence of post herpetic neuralgia.
Why is hutchingson sign so worrisome?
This will present as grouped vesicles over the nose. If this is present, this is herpes ophthalmicus until proven otherwise.
What are risk factors for HIV infection?
- Men who have sex with men
- Injection drug use
- Blood product recipients
- Needle stick injury
How are asymptomatic patients screened for HIV?
Patients are screened with ELISA. If positive, order the western blot to confirm the diagnosis.
Which HIV patients require treatment?
ALL patients should receive treatment regardless of CD4 count. This is a progressive disease!
When is prophylaxis indicated for pneumocystis? What medication is used?
Prophylaxis with trimethroprim/sulfamethoxazole is indicated when CD4 levels drop
