Abstract: A 4-year-old boy presented with erythema on palms and soles for 12 days. Dermatological examination showed that copper-colored spots on palms, fingers, and soles，moist reddish flat papules on perianal. Treponema Pallidum Particle Assay(TPPA) was positive and the Toluidine Red Unheated Serum Test(TRUST) titre was 1∶16. The case was diagnosed as acquired secondary syphilis. The lesions disappeared after intramuscular injection of benzathine penicillin. The TRUST titre was 1∶4 after treatment for 3 months The patient is under follow-up.

Key words: child, secondary syphilis