A 31-year-old woman, Fitzpatrick's phototype V, with a previous history of Human Immunodeficiency Virus (HIV) infection under treatment with Highly Active Antiretroviral Therapy (HAART), presented to our Dermatology Emergency Department with a 2-week history of asymptomatic erythematous oral and perianal lesions. The patient reported unprotected sexual intercourse with a male partner 2 months before. She denied other systemic or local symptoms. On physical examination, there were asymptomatic, firm, flat-topped erythematous plaques with a whitish surface located on the oral mucosa and perianal region (Fig. 1). Laboratory examination revealed a positive Treponema pallidum hemagglutination assay and a reactive Venereal Disease Research Laboratory test (1:64 dils). HIV viral load was undetectable and cluster of differentiation 4⁺ lymphocyte count was normal. Other sexually transmitted infections were excluded, namely hepatitis B and C, as well as gonorrhea and chlamydia (using urine polymerase chain reaction molecular testing). The diagnosis of oral and perianal condylomata lata as the only manifestation of secondary syphilis was established. The patient was treated with one administration of intramuscular benzathine penicillin, 2.4 million units, with complete resolution of the lesions (Fig. 2). Syphilis is considered the great mimicker of dermatovenereology due to its numerous different presentations, especially in the secondary stage and in HIV patients, and its recognition can challenge even the most experienced clinician¹-³. Condylomata lata is a classic, though uncommon, presentation of secondary syphilis and can sometimes be its first and only clinical manifestation². Characteristically, it presents with nontender, whitish, and verrucous plaques located on the anogenital area, although extragenital locations may occur²-⁴. This case highlights that syphilis, in all its versatile and challenging presentations, should always be kept in mind in dermatology practice.

Figure 1 A: asymptomatic, flat-topped erythematous plaques with a whitish surface, located on the oral mucosa and B: perianal region. 

Figure 2 A: complete clinical resolution of the plaques on the oral mucosa and B: perianal region after treatment.