(BMJ)—A 19-year-old man presented with a 2-month hx of scalp hair loss and lumps behind his ears and in the groin. He also complained of general malaise for the past month. Exam: painless generalized postauricular, posterior cervical, and inguinal lymphadenopathy; patchy, moth-eaten alopecia all over the scalp. Dermoscopy: yellow dots and broken hairs. Fungal microscopy negative. What’s the dx?
Hodgkin lymphoma
Alopecia areata
Syphilitic alopecia
Tinea capitis
Discoid lupus erythematosus
You are correct. Rapid plasma reagin was positive, with a titer of 1:64, and the Treponema pallidum agglutination test was also positive, confirming the dx of syphilis. Alopecia occurs in 2.9% to 7% of patients with secondary syphilis; moth-eaten alopecia is a pathognomonic manifestation of secondary syphilis. This patient's lymphadenopathy resolved within 2 weeks of starting tx with IM penicillin G benzathine. Hair growth had returned to normal at 3-month follow-up.

BMJ 2019;366:l4555