ID

Question 1

What is the definition of fever of unknown origin (FUO)?

Answer 1

Fever >38.3°C (101°F) lasting >3 weeks with no identified cause despite initial evaluation.

Question 2

What are the most common causes of FUO?

Answer 2

Infections (TB, endocarditis, occult abscess), malignancies (lymphoma, leukemia), autoimmune diseases (SLE, vasculitis), and drug-induced fever.

Question 3

What is the role of empiric antibiotics in FUO?

Answer 3

They are generally avoided unless a bacterial infection is strongly suspected, as they can obscure diagnostic findings.

Question 4

What are the most common infectious causes of chronic fatigue?

Answer 4

EBV, CMV, HIV, hepatitis, tuberculosis, Lyme disease.

Question 5

How is infectious mononucleosis differentiated from other causes of fatigue?

Answer 5

Presence of pharyngitis, posterior cervical lymphadenopathy, splenomegaly, and positive heterophile (Monospot) test.

Question 6

What is the most common causative agent of influenza?

Answer 6

Influenza A and B viruses.

Question 7

When is antiviral treatment (oseltamivir) most effective for influenza?

Answer 7

Within 48 hours of symptom onset.

Question 8

What are the most common complications of influenza?

Answer 8

Secondary bacterial pneumonia (S. aureus, S. pneumoniae), myocarditis, and Guillain-Barré syndrome.

Question 9

How is HSV-1 typically transmitted compared to HSV-2?

Answer 9

HSV-1 is primarily transmitted via saliva (oral lesions), while HSV-2 is usually sexually transmitted (genital lesions).

Question 10

What test confirms HSV infection?

Answer 10

PCR or viral culture from a vesicular lesion.

Question 11

What is the first-line treatment for HSV outbreaks?

Answer 11

Acyclovir, valacyclovir, or famciclovir.

Question 12

What is the primary infection caused by VZV?

Answer 12

Varicella (chickenpox).

Question 13

What is the characteristic distribution of herpes zoster (shingles)?

Answer 13

Dermatomal, unilateral vesicular rash.

Question 14

What is the major complication of shingles affecting the eye?

Answer 14

Herpes zoster ophthalmicus (V1 involvement of the trigeminal nerve).

Question 15

What is the classic triad of symptoms for EBV mononucleosis?

Answer 15

Fever, pharyngitis, and posterior cervical lymphadenopathy.

Question 16

Why should patients with mononucleosis avoid contact sports?

Answer 16

Risk of splenic rupture due to splenomegaly.

Question 17

What hematologic finding is characteristic of EBV?

Answer 17

Atypical lymphocytosis.

Question 18

What is the classic prodrome of measles?

Answer 18

Cough, coryza, conjunctivitis, and Koplik spots.

Question 19

What is the most feared complication of mumps?

Answer 19

Orchitis leading to infertility.

Question 20

How does congenital rubella syndrome present?

Answer 20

Sensorineural hearing loss, cataracts, and congenital heart defects (PDA, pulmonary stenosis).

Question 21

What is the most severe complication of polio?

Answer 21

Flaccid paralysis due to anterior horn cell damage.

Question 22

How is polio prevented?

Answer 22

Inactivated polio vaccine (IPV) or oral polio vaccine (OPV in endemic areas).

Question 23

What are the most common bacterial causes of meningitis in adults?

Answer 23

Streptococcus pneumoniae, Neisseria meningitidis, Listeria (in elderly).

Question 24

What cerebrospinal fluid (CSF) findings suggest bacterial vs. viral meningitis?

Answer 24

Bacterial: Elevated WBC, low glucose, high protein. Viral: Elevated WBC (lymphocytes), normal glucose, normal/mildly elevated protein.

Question 25

What is the most common organism in animal bites?

Answer 25

Pasteurella multocida.

Question 26

What is the first-line antibiotic for animal and human bites?

Answer 26

Amoxicillin-clavulanate.

Question 27

What is the first symptom of rabies?

Answer 27

Nonspecific flu-like symptoms progressing to hydrophobia, agitation, and paralysis.

Question 28

How is post-exposure prophylaxis (PEP) administered for rabies?

Answer 28

Rabies vaccine + human rabies immunoglobulin (HRIG) if not previously vaccinated.

Question 29

What are common viral causes of hemorrhagic fever?

Answer 29

Ebola, Marburg, Lassa fever, Dengue, Crimean-Congo hemorrhagic fever.

Question 30

What laboratory findings suggest viral hemorrhagic fever?

Answer 30

Thrombocytopenia, elevated liver enzymes, coagulopathy.

Question 31

How is hemorrhagic fever managed?

Answer 31

Supportive care (IV fluids, oxygen, blood products if needed).

Question 32

What is the causative organism of malaria?

Answer 32

Plasmodium species (P. falciparum most severe).

Question 33

What is the characteristic fever pattern of malaria?

Answer 33

Cyclical fevers (every 48-72 hours).

Question 34

What is the hallmark skin lesion of Lyme disease?

Answer 34

Erythema migrans (“bull’s-eye rash”).

Question 35

What tick-borne infection presents with fever, thrombocytopenia, and elevated liver enzymes?

Answer 35

Ehrlichiosis or Anaplasmosis.

Question 36

What is the treatment for Rocky Mountain Spotted Fever?

Answer 36

Doxycycline, regardless of patient age.

Question 37

What are the different forms of leishmaniasis?

Answer 37

Cutaneous, mucocutaneous, and visceral (“kala-azar”).

Question 38

What is the treatment for amebiasis?

Answer 38

Metronidazole + paromomycin.

Question 39

How does giardiasis present?

Answer 39

Foul-smelling, greasy stools and bloating after drinking contaminated water.

Question 40

What is the most common helminth infection worldwide?

Answer 40

Ascaris lumbricoides (roundworm).

Question 41

What exposure is associated with histoplasmosis?

Answer 41

Bird/bat droppings, Mississippi/Ohio River valleys.

Question 42

What is the primary treatment for disseminated histoplasmosis?

Answer 42

Itraconazole or amphotericin B.

Question 43

What is the screening test for HIV?

Answer 43

HIV antigen/antibody test (4th generation).

Question 44

What CD4 count defines AIDS?

Answer 44

<200 cells/mm³ or AIDS-defining illness (PCP, Kaposi sarcoma).

Question 45

What are rickettsial infections, and how are they transmitted?

Answer 45

Rickettsial infections are bacterial diseases caused by obligate intracellular bacteria from the Rickettsia, Ehrlichia, and Anaplasma genera. They are transmitted primarily through arthropod vectors, including ticks, lice, fleas, and mites.

Question 46

What are the most common rickettsial infections in North America?

Answer 46

Rocky Mountain Spotted Fever (RMSF), Ehrlichiosis, and Anaplasmosis.

Question 47

What is the causative organism and vector for Rocky Mountain Spotted Fever (RMSF)?

Answer 47

Rickettsia rickettsii, transmitted by the Dermacentor (dog) tick.

Question 48

What is the characteristic rash of RMSF, and how does it progress?

Answer 48

Starts as blanching maculopapular lesions on the wrists and ankles, then spreads centrally and becomes petechial. It may involve the palms and soles, which is rare in most rashes.

Question 49

What are the hallmark clinical symptoms of RMSF?

Answer 49

Fever, headache, myalgias, and a rash that spreads centrally.

Question 50

How is RMSF diagnosed?

Answer 50

Primarily clinical diagnosis (fever, headache, rash, and history of tick exposure). Serologic testing (IgM/IgG antibodies) and indirect immunofluorescence assay (IFA) can confirm, but do not delay treatment while waiting for results.

Question 51

What is the first-line treatment for RMSF, and when should it be initiated?

Answer 51

Doxycycline for all ages, including children. Treatment should be initiated immediately based on clinical suspicion, as delays increase mortality.

Question 52

What laboratory abnormalities are common in RMSF?

Answer 52

Thrombocytopenia, hyponatremia, elevated liver enzymes.