Case Report: Secondary syphilitic alopecia following non-penetrative sexual contact: a case of initial misdiagnosis.

We describe a case of secondary syphilitic alopecia following non-penetrative sexual contact that was initially misdiagnosed as alopecia areata. A 26-year-old unmarried male presented with moth-eaten patchy alopecia in the occipital region. Prior topical treatment for presumed alopecia areata at another facility was ineffective. The patient reported repeated episodes of mutual masturbation with a female massage worker two months earlier, and he noticed a small erythematous papule on the penile frenulum thereafter. Serological testing revealed a rapid plasma reagin (RPR) titer of 1:32 and a positive Treponema pallidum particle agglutination assay (TPPA), confirming syphilis. The final diagnoses were secondary syphilis and syphilitic alopecia. Treatment consisted of benzathine penicillin G, 2.4 million units intramuscularly weekly for 3 weeks. Within 3 months, complete hair regrowth was observed without scarring.