Alopecia syphilitica, from diagnosis to treatment.

Alopecia syphilitica (AS) is an uncommon manifestation of secondary syphilis, with a prevalence that ranges from 3% to 7%. It is a nonscarring alopecia that can present in a diffuse pattern, a moth-eaten pattern, or a mixed subtype. Due to its low prevalence and similar presentation to other forms of alopecia such as alopecia areata, telogen effluvium, and tinea capitis, dermatologists must maintain a high degree of suspicion for prompt diagnosis. The diagnosis of AS is made by eliciting the patient's history, obtaining serologic tests, and examining histopathologic or dermatoscopic findings. First-line treatment includes benzathine penicillin G injection, which leads to hair regrowth weeks to months after administration. In this article, we present a focused review on the diagnosis of AS and discuss evidence-based therapeutic approaches for the management and treatment of this condition.