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

A 26-year-old male was initially misdiagnosed with alopecia areata but was later found to have secondary syphilitic alopecia following non-penetrative sexual contact. The patient had moth-eaten patchy alopecia and a small erythematous papule on the penile frenulum. Serological tests confirmed syphilis, with an RPR titer of 1:32 and a positive TPPA. He was treated with benzathine penicillin G, 2.4 million units intramuscularly weekly for 3 weeks, resulting in complete hair regrowth within 3 months without scarring.