Infectious

Question 1

What is first-line treatment for malignant otitis externa (characterized by necrotizing inflammation of the external auditory canal)?

Answer 1

IV ciprofloxacin

Question 2

What are the two most common infectious causes of brain abscess in an immunocompetent patient?

Answer 2

Strep viridans and Staph aureus (from infected adjacent tissues such as sinuses or otitis media)

Question 3

What viruses should patients be tested for with idiopathic thrombocytopenia purpura (ITP)?

Answer 3

Both HIV and hepatitis C can decrease platelet counts

Question 4

What is Ramsay Hunt syndrome?

Answer 4

Bell’s palsy caused by herpes zoster. Vesicles are typically seen on the outer ear

Question 5

What is the classic triad of invasive pulmonary aspergillosis and how does it appear on CT chest?

Answer 5

Fever, pleuritic chest pain, and hemoptysis. Appears as nodules with surrounding ground-glass opacities (halo sign).

Question 6

What are features of HSV retinitis?

Answer 6

Affects immunocompromised patients (e.g. HIV). Characterized by rapidly progressing bilateral necrotizing retintis (initially will present with keratitis and conjunctivitis with eye pain, followed by rapidly progressive visual loss). Fundoscopic exam reveals widespread, pale, peripheral lesions and central necrosis of the retina.

Question 7

How does CMV retinitis present?

Answer 7

Painless visual loss. Funduscopy shows fluffy or granular retinal lesions located near the retinal vessels and associated hemorrhages.

Question 8

What is a bright red, firm, friable, exophytic nodule in an HIV infected patient most likely?

Answer 8

Bacillary angiomatosis - from a Bartonella infection

Question 9

What medication is indicated for mild-moderate C. diff and what medication is indicated for severe C. diff infections?

Answer 9

Mild-moderate: oral metronidazole

Severe: Oral vancomycin

Question 10

In a patient who has previously received a rabies vaccine, what interventions are needed if they are bitten by a reservoir animal?

Answer 10

Just a repeat vaccine, no need for immunoglobulin

Question 11

What is the treatment for Pneumoncystis pneumonia (PCP)?

Answer 11

Preferred: TMP-SMX plus adjunctive corticosteroids.

Alternatives include dapsone, atovaquone, and primaquine

Question 12

What are common symptoms in disseminated Mycobacterium avium complex (MAC) infection?

Answer 12

Nonspecific symptoms (e.g. fever, cough, abdominal pain, diarrhea, night sweats, weight loss, etc) in the presence of splenomegaly and elevated alk phos

Question 13

What area of the lungs to TB most often infect?

Answer 13

The apices (high oxygen tensions and slower lymphatic elimination.

Question 14

What is the treatment of choice for pregnant/lactating women and children <8 yrs with early Lyme disease?

Answer 14

Amoxicillin

Question 15

What is the workup for Pneumocystis pneumonia?

Answer 15

Increased LDH levels, diffuse reticular infiltrates on imaging, and induced sputum or BAL (stain)

Question 16

What is tick-borne paralysis?

Answer 16

Pts present with progressive ascending paralysis over hours to days. There is not a prodromal illness or fever. CSF examination is usually normal. Due to release of neurotoxin from the tick (takes 4-7 days of feeding). Removing the tick results in complete recovery

Question 17

What is the treatment for scabies?

Answer 17

Topical 5% permethrin or oral ivermectin

Question 18

What GI infection is associated with bloody diarrhea in the absence of fever?

Answer 18

E. coli

Question 19

What empiric antibiotic coverage should patients have if they have febrile neutropenia if the neutropenia is severe?

Answer 19

Anti-pseudomonal coverage

Question 20

What patients are most at risk for serious Vibrio vulnificus infections?

Answer 20

Patients with liver disease, especially hemochromatosis (increased iron levels act as a growth catalyst) - at risk for necrotizing fasciitis

Question 21

What PNA are pts with COPD at risk for?

Answer 21

H. influenzae

Question 22

What does an alcoholic patient with current jelly sputum likely have?

Answer 22

Klebsiella PNA

Question 23

How is neutropenic fever treated?

Answer 23

3rd or 4th gen cephalosporin (ceftazidime or cefipime)
– Add vanc if line infxn suspected or if septic shock develops.
– Add amphoB if no improvement and no source found in 5 days.

Question 24

What is neutropenic fever?

Answer 24

• Defined by a single temp > 101.3 or sustained temp >100.4 for 1hr. ANC < 500.
• Mucositis 2/2 chemo causes bacteremia (usually from gut)
• MC bugs are pseudomonas or MRSA (if port present).

Question 25

What exam should you never do in a patient with neutropenic fever?

Answer 25

Digital rectal exam - can cause translocation of gut flora across the wall because they have mucositis

Question 26

What are symptoms of a cavernous sinus thrombus?

Answer 26

Headache that can become intolerable is most common. Patients often have a low-grade fever and periorbital edema that develops several days after the headache. Pts may also get increased ICP with papilledema and vomiting. Can have unilateral or bilateral cranial nerve (III, IV, V, and VI) palsies

Question 27

What organism is responsible for most deep infections following puncture wounds?

Answer 27

Pseudomonas aeruginosa

Question 28

What is the presentation of ehrlichiosis?

Answer 28

After a tick bite (southeastern and south central US - lone star tick). Flu-like illness (fever, HA, myalgias, chills), confusion, rash uncommon, leukopenia, and thrombocytopenia. Can also have elevated LFTs.
Treat with doxycycline

Question 29

What is the treatment of choice for bacterial conjunctivitis?

Answer 29

Topical erythromycin

Question 30

What are symptoms of dengue fever?

Answer 30

Retro-orbital pain, fever, malaise, and myalgia are typically described by patients who have contracted dengue, and are accompanied by exanthem (maculopapular rash) and lymphadenopathy. There are typically hematologic findings such as leukopenia and thrombocytopenia

Question 31

What medication should HIV positive patients be taking prophylactically if they live in the Ohio and Mississippi river valleys with a CD4 count <150?

Answer 31

Itraconazole for Histoplasma capsulatum