Quick tip for estimating CD4 count in ED
CD4 < 200 significantly raises risk for opportunistic infections.
- Absolute lymphocyte count < 1000 correlates to CD4 count < 200.
- Absolute lymphocyte count > 2000 correlates to CD4 count > 200.
Patient with CD4 <200 or ALC <1000
- Even vague complaints including fever, headache, and/or malaise may have CNS infections.
- Obtain CT followed by LP.
- CSF WBC counts and glucose may appear normal despite a concomitant CNS infection
- Initiate empiric treatment until cutlures and antigen testing returns.
- Consider CT with and without contrast
- Contrast shows ring-ehanching lesions of toxoplasmosis.
Patient with CD4 >200 or ALC >2000
- Clinical decision rule developed in cohort of 110 HIV positive patients.
- 100% sensitivity in ruling out new intracranial lesions
- New or different headache than usual?
- Headache lasting more than three days?
- Focal neurologic deficit?
- Altered mental status?
- New-onset seizure?
- If none of these are present, it is considered safe to forego CT and LP.
Special considerations in differential for HIV pt w/ CNS symptoms
- Includes fever, malaise, headache, focal weakness, etc.
- Cryptococcal meningitis
- Toxoplasma gondii
- Progressive multifocal leukoencephalopathy
- CNS lymphoma
Core Content, infectious disease, neurology