Master the Boards: Infectious Disease

Question 1

If a patient has a rash to penicillin then what antibx do you recommend?

If a patient has an anaphylactic reaction to penicillin then what antibx do you recommend?

Answer 1

Rash: Cephalosporin

Anaphylaxis: Non-beta-lactam

Question 2

2nd gen cephs have added coverage to ______ compared to 1st gen cephs.

Answer 2

Added anaerobe and more gram-negative bacilli

Question 3

Why should ceftriaxone be avoided in neonates?

What 3rd gen cephalosporin has Pseudomonal coverage?

Answer 3

Ceftriaxone may cause impaired bilirubin metabolism

Cefotaxime

Question 4

Name a 4th gen ceph

Answer 4

Cefepime

Question 5

What is an important adverse effect of cefoxitin and cefotetan?

Answer 5

Depletion of prothrombin and increased risk of bleeding

Question 6

What unique coverage does aztreonam have?

Does it cross-react with penicillin?

Answer 6

Only gram-negative bacilli, including Pseudomonas

No cross-reaction with penicilllin

Question 7

Fluoroquinolones have coverage of what bacteria?

Which fluoroquinolone also has anaerobic coverage?

Answer 7

Gram negative bacilli, including Pseudomonas

Moxifloxcin has anaerobe coverages (thus can be used as a single agent in the treatment of diverticulitis i.e metronidazole doesn’t have to be added)

Question 8

Do aminoglycosides have any anaerobic effect?

What are the major toxicities?

Answer 8

No.

Nephrotoxic, ototoxic

Question 9

Cystitis in pregnant woman is best treated with _____.

Answer 9

NItrofurantoin

Question 10

Fanconi Syndrome (Type II renal tubular acidosis proximal), photosensitivity, and esophagitis/ulcer are all adverse effects of _____.

Answer 10

Doxycycline

Question 11

Patients allergic to penicillin but requiring treatment of syphillis may receive _________.

Answer 11

Doxycycline

Question 12

What drug can cause both G6PD deficiency hemolysis and bone marrow suppresion?

Answer 12

Trimethoprim/Sulfamethoxazole

BM suppression because it’s a folate antagonist

Question 13

What are your choices for tx of MRSA (5)?

What if it was a minor skin infection?

Answer 13

Vancomycin
Linezolid
Daptomycin
Tigecycline
Ceftaroline

Minor skin infection: TMP/SMX, Clindamycin, Doxycycline, Linezolid

Question 14

You’re treating a MRSA patient and they develop elevated CPK levels, what are you treating with?

What if they showed signs of bone marrow toxicity?

Answer 14

Daptomycin: Elevated CPK

Linezolid: Reversible bone marrow toxicity

Question 15

The presence of papilledema, seiures, focal neurologic deficits, or confusion should warrant what exam before conducting an LP in suspected meningitis?

Answer 15

CT head to r/o space-occupying lesion

Question 16

What is empiric treatment of meningitis prior to knowledge of culture results?

What should be added to that therapy if the patient is neonate, old, immunocompromised, or pregnant?

Answer 16

Ceftriaxone, vancomycin, steroids

Add ampicillin for fear of Listeria infection

Question 17

What is the most common neurological deficit in untreated bacterial meningitis?

Answer 17

CN 8 damage or deafness

Question 18

Acyclovir has what adverse effect to keep in mind?

Answer 18

Renal toxicity since it precipitates in renal tubules

Question 19

Is the radiologic test usually the answer in an ID question about the “most accurate test”?

Answer 19

No

Question 20

Small vesicles or ulcers ID’d on exam of a patient with pharyngitis could move you towards what other two diagnoses?

Answer 20

HSV or Herpangina

Question 21

Blood and WBC in stool in a patient with hemochromatosis or a recent blood transfusion may be cause by what pathogen?

Answer 21

Yersinia (has a high affinity for iron)

Question 22

A patient eats some spoiled fish and develops wheezing, flushing, and a rash. What is the cause and what is the tx?

Answer 22

Scombroid

Anti-histamine

Question 23

Elevation of which lab in hepatitis is associated with increased risk of mortality?

Answer 23

Prothrombin time (PT)

Question 24

In addition to gram positive bacteria, what additional coverage to amoxicillin and ampicillin provide?

Answer 24

Other gram-negative bacilli

H. influenzae, E. coli, Listeria, Proteus, Salmonella

Question 25

Does cystitis give urethral discharge?

Answer 25

No

Question 26

A woman presents with symptoms of PID. What should you do before moving forward with treatment?

Answer 26

Rule out pregnancy

Question 27

STD buzzwords Painful ulcer

Answer 27

Chancroid (H. ducreyi)

Question 28

STD buzzwords Tender lymph nodes and suppurating

Answer 28

Lymphogranuloma venereum

Question 29

Rank tests for determining syphilis based on accuracy or sensitivity

Answer 29

VDRL/RPR

Question 30

Best initial test for determining HSV? Most accurate?

Answer 30

Best initial: Tzanck smear Most accurate: Viral culture

Question 31

What diagnostic tests are used to confirm lymphogranuloma venereum?

Answer 31

Complement fixation titers in blood | Nucleic acid amplification testing on swab

Question 32

Tx Chancroid

Answer 32

Azithromycin (single dose)

Question 33

Tx Lymphogranuloma venereum

Answer 33

Doxycycline

Question 34

Patients with syphilis are at greater risk for what vascular complication?

Answer 34

Aortic aneurysm and aortic regurgitation

Question 35

What is the treatment of syphilis in each stage (primary, secondary, and tertiary) and how does it change if penicillin allergic?

Answer 35

Primary and secondary: single dose IM benzathine penicillin (Doxycycline if allergic) Tertiary: IV penicillin (penicillin desensitization if allergic)

Question 36

What is a Jarisch-Herxheimer reaction and what is treatment?

Answer 36

Fever and worsening of symptoms after treating syphilis patient with penicillin Give aspirin and antipyretics, it will pass on its own

Question 37

What causes condyloma acuminate?

Answer 37

aka genital warts HPV

Question 38

A patient comes in with intense itching at his pubis and axilla (hair-bearing regions). You suspect pediculosis (crabs). What is tx?

Answer 38

Permehrin | Lindane can also be used but has more toxicity

Question 39

What presents in the web spaces of the fingers and toes and burrows in the skin? What must be done to confirm a diagnosis? What is tx?

Answer 39

Scrape and magnify the burrows to dx Treat with permethrin

Question 40

A patient presents with likely pyelonephritis but fails to improve on antibx therapy. What should be the next test done?

Answer 40

Imaging using ultrasound or CT to evaluate for a perinephric abscess and if present it must be drained

Question 41

What is the best initial therapy in suspected endocarditis prior to results of cultures?

Answer 41

Vancomycin and gentamicin

Question 42

What is the treatment of Viridans Strep endocarditis?

Answer 42

Ceftriaxone

Question 43

What is the treatment of Enterococci endocarditis?

Answer 43

Ampicillin and gentamicin

Question 44

What drug should be added to the treatment of Staph endocarditis if there is a prosthetic valve involved?

Answer 44

Rifampin

Question 45

When should surgery be considered in endocarditis (6)?

Answer 45

``` CHF or ruptured valve/chordae tendinae Prosthetic valves Fungal endocarditis Abscess AV block Recurrent emboli while on tnibx ```

Question 46

What is the most common agent responsible for culture-negative endocarditis? What are the HACEK organisms?

Answer 46

MC: Coxiella (also Bartonella) | ``` Use ceftriazone for HACEK organisms Haemophilus Actinobacillus Cardiobacterium Eikenella Kingella ```

Question 47

What is endocarditis prophylaxis? In what situations would you offer the prophylaxis?

Answer 47

Amoxicillin Significant cardiac defect: previous endocarditis, prosthetic valve, recent cardiac txp, unrepaired cyanotic heart disease Risk of bacteremia: Dental procedure W/ blood, respiratory tract surgery that produces bacteremia

Question 48

What is the most common neurologic and cardiac manifestation, respectively, of Lyme disease?

Answer 48

Neurlogic: Bell's Plasy Cardiac: AV block

Question 49

What is generally the treatment of Lyme disease? When it is advanced and involves cardiac or neurologic manifestations then what is tx?

Answer 49

Doxycycline If advanced: IV ceftriaxone

Question 50

Do patients with an asymptomatic tick bite receive ppx?

Answer 50

Generally no. They only receive a single dose of doxycyline if the tick was identified as Ixodes scapularis, the area is engorged, the tick was present on skin for 24-48 hours.

Question 51

Is ELISA an effective test for evaluating HIV in neonates?

Answer 51

No. They need PCR or viral culture

Question 52

What is the best initial test for detecting HIV infection? What is confirmatory?

Answer 52

Initial: ELISA Confirmatory: Western Blot

Question 53

Generally, what are each type of agent with the following names: - navir - udine/-bine

Answer 53

- navir: protease inhibitors | - udine/-bine: NRTIs

Question 54

What are two entry inhibitors used in HIV? What is an integrase inhibitor?

Answer 54

Entry inhibitors: Enfuvirtide, Maraviroc Integrase inhibitor: Raltegravir

Question 55

HIV adverse effect Zidovudine

Answer 55

Anemia

Question 56

HIV adverse effect Stavudine and didanosine

Answer 56

Peripheral neuropathy and pancreatitis

Question 57

HIV adverse effects Abacavir

Answer 57

Hypersensitivity, Stevens-Johnson reaction *Hypersensitivity is indicated by HLA B5701 status

Question 58

HIV adverse effects Protease inhibitors

Answer 58

Hyperlipidemia, Hyperglycemia

Question 59

HIV adverse effects Indinavir

Answer 59

Nephrolithiasis

Question 60

HIV adverse effects Tenofovir (NRTI)

Answer 60

Renal insufficiency

Question 61

Can HIV medications generally be continued in pregnancy? What is one drug avoided due to teratogenicity in animals?

Answer 61

Yes Efavirenz is avoided (if already on prior to becoming pregnant then change to a protease inhibitor)

Question 62

In what situations should a C-section be considered in an HIV positive pregnant woman?

Answer 62

If the CD4 count is 1000). Zidovudine is given no matter what to reduce risk of vertical transmission