Master the board step 3

Master the Boards: USMLE Step 3
Treatment
··
Azithromycin and atovaquone
Ehrlichia/Anaplasma
This, too, is transmitted by the Ixodes tick. There is no rash. Instead, there are
elevated liver function tests (ALT and AST), thrombocytopenia (decreased
platelets), and leukopenia (decreased white blood cells).
Diagnostic Testing
Diagnose with a peripheral blood smear looking for “morulae,” which are
inclusion bodies in the white cells, or do PCR.
Treatment
··
Doxycycline
Malaria
This disease is rarely domestic. Look for a traveler recently returning from an
endemic area with hemolysis. GI complaints are always present.
Diagnostic Testing
··
Blood smear
The same drugs can be
used for acute treatment
and prophylaxis of malaria:
••
Mefloquine
••
Atovaquone/proguanil
Treatment
··
Acute disease is treated with mefloquine or atovaquone/proguanil or
quinine/doxycycline in very severe cases.
··
Prophylaxis is with mefloquine (weekly) or atovaquone/proguanil
(Malarone; administered daily). Daily doxycycline has been used for prophylaxis
but would not be the best answer. Those being given mefloquine
should be advised of neuropsychiatric side effects, sinus bradycardia, and
QT prolongation.
Respiratory Diseases
Nocardia
Nocardia gives branching,
gram-positive filaments
that are weakly acid fast.
This involves immunocompromised people (leukemia, lymphoma, steroid
use, HIV). Respiratory/pulmonary disease may disseminate to any organ, with
skin and brain being the most common.
Diagnostic Testing
··
Best initial test: Chest x-ray
··
Most accurate test: Culture
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