Infectious Disease

Question 1

What two organ systems does cryptococcus most commonly affect?

Answer 1

1. CNS


2. Lungs

Question 2

How is cryptococcus treated?

Answer 2

CNS is treated with amphotericin B, followed by fluconazole.
 Lung involvement is treated with fluconazole.

Question 3

What findings are seen on chest x-ray in histoplasmosis?

Answer 3

Hilar or mediastinal lymphadenopathy with focal infiltrates. Don’t confuse this with sarcoidosis!

Question 4

When is pneumocystis jirovecii usually diagnosed?

Answer 4

In aids patients with a CD4 count

Question 5

What chest x-ray finding is usually seen in pneumocytis?

Answer 5

Bilateral interstitial infiltrates.

Question 6

What infection leads to rheumatic fever?

Answer 6

Group A strep pharyngitis. Group A strep from skin infection will not lead to rheumatic fever.

Question 7

What is the treatment of choice for rheumatic fever?

Answer 7

Penicillin. If allergic, give a cephalosporin. If severe allergy is present, give a macrolide or clindamycin.

Question 8

Why should raw honey never be given to infants?

Answer 8

Increased risk of botulism.

Question 9

How do patients with botulism classically present?

Answer 9

Classically, they will present with descending weakness/paralysis. This is in contrast to GBS, which present with ascending weakness/paralysis.

Question 10

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?

Answer 10

This is the classic presentation for cholera.

Question 11

How is the diagnosis of active tuberculosis made?

Answer 11

Patients are diagnosed with acid fast bacilli smear and sputum culture collected over 3 consecutive days.

Question 12

What is the treatment of choice for tuberculosis?

Answer 12

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.

Question 13

When is PPD done?

Answer 13

Is done in asymptomatic patients only. This is a screening test and should not be used for diagnosis.

Question 14

What should always be given with isoniazid? Why?

Answer 14

Vitamin B6 (pyridoxine) to prevent peripheral neuropathy.

Question 15

HIV patient has a head CT scan showing multiple ring enhancing lesions. What is
the next best step in management?

Answer 15

Empiric treatment with:

1. pyrimethamine and sulfadiazine

or

2. clindamycin

Question 16

When is prophylaxis indicated for lyme disease?

Answer 16

Prophylaxis indicated when:


1. Deer tick identified

2. Attached >36 hours

3. Doxycyline can be given within 72 hours

4. Lives in endemic area

5. Does not have contraindication to doxycycline

Question 17

What is the treatment of choice for lyme disease?

Answer 17

8 give doxycycline

Question 18

Describe the rash seen in rocky mountain spotted fever.

Answer 18

Patients will classically present with a rash that starts at the ankles and wrists and moves centrally. The palms and soles are commonly affected.

Question 19

What is Jarisch-Herxheimer reaction?

Answer 19

This occurs during penicillin treatment for syphilis. Fever, myalgia, and headache occurs within the first 24 hours of treatment.

Question 20

When evaluating EBV mononucleosis, a heterophil test is ordered. The test is negative. What is the next lab that should be ordered?

Answer 20

The next test is EBV specific antibodies.

Question 21

When should the Zoster vaccine be given?

Answer 21

It is recommended in patients >60 years of age. Be aware that it is FDA approved in patients >50 years of age.

Question 22

What is the main purpose for treating herpes zoster with antivirals?

Answer 22

The main reason is to reduce the incidence of post herpetic neuralgia.

Question 23

Why is hutchingson sign so worrisome?

Answer 23

This will present as grouped vesicles over the nose. If this is present, this is herpes ophthalmicus until proven otherwise.

Question 24

What are risk factors for HIV infection?

Answer 24

1. Men who have sex with men

2. Injection drug use

3. Blood product recipients
4. Needle stick injury

Question 25

How are asymptomatic patients screened for HIV?

Answer 25

Patients are screened with ELISA. If positive, order the western blot to confirm the diagnosis.

Question 26

Which HIV patients require treatment?

Answer 26

ALL patients should receive treatment regardless of CD4 count. This is a progressive disease!

Question 27

When is prophylaxis indicated for pneumocystis? What medication is used?

Answer 27

Prophylaxis with trimethroprim/sulfamethoxazole is indicated when CD4 levels drop