Master the board step 3

Master the Boards: USMLE Step 3
A 17-year-old male is brought to the emergency department with fever, headache,
stiff neck, and photophobia. He has a petechial rash. CSF shows 2,499 neutrophils.
Ceftriaxone and vancomycin are started. What should be done next?
a. Test for HIV
b. Wait for results of culture
c. Add ampicillin
d. Enforce respiratory isolation
e. Enforce respiratory isolation and prescribe rifampin for close contacts
Answer: E. When an adolescent presents with a petechial rash and increased neutrophils
on CSF, it is suggestive of Neisseria meningitidis. These patients should be placed
on respiratory isolation, and close contacts should receive prophylaxis.
Listeria
Look for elderly, neonatal, and HIV-positive patients and those with who have
no spleen, are on steroids, or are immunocompromised with leukemia or
lymphoma.
There will be elevated neutrophils in the CSF. Add ampicillin to therapy.
The nurse or medical
student taking care of a
patient with Neisseria does
not need prophylaxis.
Those with kissing and
other saliva-type contact
do need prophylaxis.
Neisseria meningitidis
Look for patients who are adolescent, in the military, or asplenic or who have
terminal complement deficiency.
Treat as follows:
··
Patient: Begin respiratory isolation.
··
Close contacts: Start prophylaxis with rifampin, ciprofloxacin, or ceftriaxone
for close contacts, such as household members and those who share utensils,
cups, or kisses.
··
Routine contacts: Routine school and work contacts do not need to receive
prophylaxis.
Encephalitis
Fever + Confusion =
Encephalitis
Look for a patient with fever and altered mental status over a few hours. If the
patient also has photophobia and a stiff neck, you will not be able to diagnose
encephalitis. Almost all encephalitis in the United States is caused by herpes.
The patient does not have to recall a herpes infection in the past for the condition
to be herpes encephalitis.
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