Master the board step 3

Infectious Diseases
Maintenance therapy is with oral valganciclovir lifelong, unless the CD4 goes
up with HAART. If the CD4 rises, you can stop the CMV medications.
Cryptococcus
HIV and < 50 CD4 cells with fever and headache. Neck stiffness and photophobia
are not always present. Perform a lumbar puncture, finding an
increase in the level of lymphocytes in the CSF. The best initial test is an India
ink stain, which has about a 60 percent sensitivity. The most accurate test is
a cryptococcal antigen test, which is over 95 percent sensitive and specific.
Treat initially with amphotericin and 5-FC, followed by fluconazole. The
fluconazole is continued lifelong unless the CD4 count rises. If the CD4 count
rises, all opportunistic infection treatment and prophylaxis can be stopped.
The only treatment that cannot be stopped is the antiretrovirals.
Echinocandins such as
caspofungin do not cover
cryptococcus.
HIV test everyone, no
matter their risk.
Progressive Multifocal Leukoencephalopathy (PML)
HIV and < 50 CD4 cells with focal neurologic abnormalities. The best initial
test is a head CT or MRI. The lesions do not show ring enhancement and there
is no mass effect. PCR of CSF for JC virus is most accurate.
There is no specific therapy available for PML. Treat with HAART. When the
CD4 count rises, PML will resolve.
Mycobacterium Avium-Intracellulare (MAI)
HIV and < 50 CD4 cells. There is wasting with weight loss, fever, and fatigue.
Anemia is frequent from invasion of the bone marrow. Increased alkaline
phosphatase and GGTP with a normal bilirubin is characteristic of hepatic
involvement.
Diagnostic testing: Bone marrow is more sensitive. Liver biopsy is the most
sensitive. Blood culture is the least sensitive.
Treatment: Clarithromycin and ethambutol. Prophylaxis with azithromycin.
Rifabutin is sometimes added to therapy.
Animal-Borne Diseases
Below this box is the 90th
percentile area. This is
lower-yield material. If
you only need to pass the
exam, you do not need
to read this. If you do not
have a residency yet, and
your Step 3 grade will be
seen to make an admission
decision, you should read
and learn the material
below to try to get a 95
or higher.
Leptospirosis
This is a spirochete. There is some form of exposure to animals in the history.
The patient has eaten food contaminated by the urine of infected animals.
There is fever, abdominal pain, and muscle aches as well. Severe disease leads
to altered mental status.
Diagnostic Testing and Treatment
Diagnose with serology. Treat with ceftriaxone or penicillin.
Animal exposure + Jaundice
+ Renal = Leptospirosis
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