HIV-Associated Syphilis

Unusual manifestations include negative serologic examination for syphilis in the presence of active secondary syphilis.
Relapse after treatment that should have been adequate.
Fulminant cutaneous lesions with induration.
Necrosis and fulminant neurosyphilis resulting in permanent neurologic deficits.

Points to Remember

If syphilis is suspected in an HIV-infected patient and the serologic test is negative, then a skin biopsy should be performed.
The only medication for the treatment of syphilis that adequately penetrates the blood-brain barrier is intravenous aqueous penicillin, which should be given at a dosage of 2 to 4 million units every 4 hours for 10 to 14 days in cases of suspected or proven neurosyphilis. Patients allergic to penicillin should undergo desensitization.