A 38-year-old man was referred by his doctor to the emergency department for assessment of a lesion on his lower lip that had been present for a month and a half.

He has a personal history of unaffiliated hepatitis, tonsillectomy in childhood and a homosexual habit.

One and a half months ago, the patient noticed the appearance of a lesion on his lower lip that partially improved after treatment with acyclovir by his GP but worsened when he stopped taking it. The patient also reported lesions on the scrotum and left foot of recent onset.

Physical examination revealed a 2 cm ulcerated lesion on the left side of the vermilion of the lower lip, with an indurated base, not painful on palpation. The neck was negative for adenopathy. No other lesions were observed in the head and neck area. Simultaneously, on the left foot there was a 0.5 cm interdigital ulcerated lesion with a smooth surface and serous exudate and multiple smaller, rounded, copper-red, painless to the touch macules on the sole of the same foot. Finally, he had several small lesions on the scrotum (smaller than 0.5 cm) with an ulcerated appearance in different stages of resolution and painful to palpation. The rest of the physical examination was within normal limits.

A biopsy of the lip lesion was performed, which was inconclusive, and laboratory tests were requested to screen for HBV (HBsAg: negative, Anti-HBc: positive, quantitative Anti-HBs: >1000 mIU/ml -positive), HCV (G-ELISA: negative), HIV (Immunoblot: positive, IgG ELISA: positive, ELISA (2nd technique): positive, Load (Chiron): 3.69 Log HIV-RNA copies/ml, Lymphocyte population (CD 3+): CD 4: 43%, CD 8: 56%, CD 4/CD8 ratio: 0.77, CD 4 absolute values: 762 cells/ul, CD 8 absolute values: 992 cells/ul), syphilis (RPR: 1/64 Positive. HAART: Positive. ELISA capture G: Positive (treponemal test)) and tuberculosis (Mantoux: negative). No complementary CSF study was performed due to the absence of neurological symptoms and short evolution.

With the diagnosis of syphilis in a patient with HIV, the patient was treated with a single dose of Penicillin G Benzathine (2.4 mill U) i.m. with complete resolution of the lesions in two weeks. Serological control at 6 months confirmed the resolution of the picture.