You can get heat rash under your arms for a lot of the same reasons that ... you try using a lotion that can calm inflammation. Syphilis is a sexually transmitted bacterial illness.

Treatments for arm rashes will depend on the underlying cause ... although not necessarily in the armpits. Syphilis, for instance, can cause a rash anywhere on the body in the secondary stage.

The classic features of secondary syphilis are skin rash (generalized, with prominence on the palms and soles), lymphadenopathy, and mucous membrane involvement with mucous patches or condylomata ...

A 20-year-old male German student presented with a bilateral speckled rash, most prominent on the ... establishing the diagnosis of secondary syphilis despite the absence of any history of primary ...