Infectious Diseases (Infections)

Question 1

All CNS infections can lead to…

Answer 1

Seizures

Question 2

CNS Infection symptoms: Stiff neck, photophobia, meningismus

Answer 2

Diagnosis: Meningitis

Question 3

CNS Infection symptoms: Confusion

Answer 3

Diagnosis: Encephalitis

Question 4

CNS infection symptoms: Focal neurological findings

Answer 4

Diagnosis: Abscess

Question 5

What are the most common causes of meningitis?

Answer 5

Streptococcus pneumonia (60%)
Group B Streptococci (14%)
Haemophilus influenzae (7%)
Neisseria meningitidis (15%)
Listeria (2%)

Question 6

What are the differences in presentation between Lyme disease and Rickettsia?

Answer 6

Lyme: Rash shaped like a target, joint pain, facial palsy, tick remembered in 20%
Rickettsia: Rash moves from arms/legs to trunk; tick remembered in 60%

Question 7

What is the best initial and most accurate test for CNS infections?

Answer 7

Lumbar puncture

Question 8

When would you expect to see a CSF evaluation with a cell count in the 1000s and the presence of neutrophils?

Answer 8

Bacterial meningitis

Question 9

When is a head CT necessary prior to LP for CNS infections?

Answer 9

When there is a possibility that a space occupying lesion may cause herniation…

• Papilledema
• Seizures
• Focal neurological abnormalities
• Confusion interfering with neurological examination

Question 10

What is the best course of action in treating CNS infection when there is a contraindication to immediate LP?

Answer 10

Give antibiotics

Question 11

When is a bacterial antigen test indicated for CNS infection?

Answer 11

When the patient has received antibiotics prior to the LP and the culture may be falsely negative

Question 12

What is the most accurate diagnostic test or the following…
Tuberculosis:
Lyme and Rickettsia:
Cryptococcus:

Answer 12

Tuberculosis: Acid fast stain and culture on 3 high volume lumbar punctures
Lyme and Rickettsia: Specific serologic testing, ELISA, western blot, PCR
Cryptococcus: India ink is 60-70% sensitive; Cryptococcal antigen is >95% sensitive and specific (culture is 100% specific)

Question 13

What is the best initial treatment of bacterial meningitis?

When would you add Ampicillin?

Answer 13

Ceftriaxone, vancomycin and steroids

Add ampicillin if immunocompromised for listeria

Question 14

Listeria is resistant to all ___________

Answer 14

cephalosporins

Question 15

What are the risk factors for listeria (require addition of ampicillin to treatment)?

Answer 15

Elderly
Neonates
Steroid use
AIDs or HIV
Immunocompromised (including alcoholism)
Pregnant

Question 16

What is given to close contacts of patients with Neisseria meningitidis?
What is meant by “close contacts”

Answer 16

Rifampin, ciprofloxacin, or ceftriaxone

Close contacts: Those who have major respiratory fluid contact

Question 17

What is the most common cause of encephalitis?

Answer 17

Herpes simplex

Question 18

What is most accurate test of herpes encphalitis

Answer 18

PCR of CSF

Question 19

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

Answer 19

Eighth cranial nerve deficit or deafness

Question 20

What is the best initial therapy for herpes encephalitis?

Answer 20

Acyclovir

Question 21

What is used to treat acyclovir-resistant herpes?

Answer 21

Foscarnet

Question 22

What is a dangerous side effect of acyclovir and foscarnet?

Answer 22

Renal toxicity because the medication precipitates in the renal tubules (foscarnet has more renal toxicity)

Question 23

How does Otitis media present?

Answer 23

Redness, immobility, bulging, and a decreased light reflex of the tympanic membrane

Question 24

What is the most sensitive physical finding for otitis media?

Answer 24

Immobility (fully mobile tympanic membrane essentially excludes otitis media)

Question 25

What is the most accurate diagnostic test for otitis media?

Answer 25

Tympanocentesis for a sample of fluid for culture

Question 26

When is tympanocentesis used in the diagnosis of otitis media?

Answer 26

Multiple recurrences or no response to multiple antibiotics

Question 27

What is the best initial therapy for otitis media?

Answer 27

Amoxicillin

Question 28

If amoxicillin is ineffective in treating otitis media, what else can be used/added?

Answer 28

Amoxicillin/clavulanate Azithromycin, clarithromycin Cefuroxime, loracarbef Levofloxacin, gemifloxacin, moxifloxacin (contraindicated in children)

Question 29

What is the most accurate diagnostic test for sinusitis?

Answer 29

Sinus biopsy or aspirate

Question 30

When is a biopsy needed for sinusitis?

Answer 30

Infection frequently recurs | There is no response to different empiric therapies

Question 31

What is the presentation of sinusitis?

Answer 31

Facial pain, discolored nasal discharge, bad taste in mouth, and fever

Question 32

What are the first-line therapies for both otitis and sinusitis?

Answer 32

Amoxicillin/clavulinic acid, doxycycline, and TMP/SMX | a decongestant is also used to promote sinus drainage

Question 33

How does pharyngitis present?

Answer 33

``` Pain on swallowing Enlarged lymph node in the neck Exudate in the pharynx Fever No cough and no hoarseness ```

Question 34

What is the best initial test for pharyngitis?

Answer 34

Rapid strep test

Question 35

What type of pharyngitis produces a positive rapid strep test? What type presents with small vesicles or ulcers? Membranous exudates?

Answer 35

Rapid strep test: Group A beta hemolytic streptococci Small vesicles/ulcers: HSV or herpangina Exudates: Diptheria, vincent angina, or EBV

Question 36

How is pharyngitis treated?

Answer 36

Penicillin or amoxicillin is the best initial therapy

Question 37

How is pharyngitis treated in penicillin allergic patients (2 answers depending on type of allergic reaction)?

Answer 37

Cephalexin if the reaction is only a rash | Clindamycin or a macrolide if allergy is anaphylaxis

Question 38

How does influenza present?

Answer 38

``` Arthralgias/myalgias Cough Fever Headache and sore throat Nausea, vomiting, or diarrhea (especially in children) ```

Question 39

What are the treatment regulations for influenza?

Answer 39

Less than 48 hours of symptoms: Oseltamivir, zanamivir; neuraminidase inhibitors shorten duration of symptoms More than 48 hours: Symptomatic treatment only