2. First appearing a month ago, this rash was first confined to the patient’s abdomen and subsequently spread. The blanchable, erythematous papules and nodules are fairly dense, uniformly covering most of his skin but sparing face and soles. Two 7-mm scaly brown nodules are seen on his right palm. There are no palpable nodes in the usual locations. More than 10 years ago, the patient was diagnosed with HIV, which is well controlled with medication. Homosexually active, he denies having any new contacts.
Diagnosis: This case presents a fairly typical clinical picture of secondary syphilis—a diagnosis that requires confirmation with syphilis serology: rapid plasma reagin (RPR) or Venereal Disease Research Laboratory (VDRL) testing. The latter measures antibodies to the lipids formed by the host against lipids formed on the treponemal cell surface.
In this case, the diagnosis had to be confirmed by more specific treponemal tests, usually conducted by the local health department, to which positive results must be reported. If further testing confirms the diagnosis (as expected), the patient will be treated by the health department. Investigators will question him, attempting to determine the source of the infection and thereby quell an outbreak.
For more information on this case, see “Unusual Cause for Asymptomatic Rash.” Clin Rev. 2013;23(9):W6.