Secondary syphilis-related oral mucous patches

A 50-year-old women presented with a 2-month history of sore throat and whitish oral lesions. She also complained of an asymptomatic ulcerative lesion on the labia majora, which had appeared 6 months previously and spontaneously disappeared after 1 month. Her past medical and dermatological histories were unremarkable. The oral examination revealed several serpiginous whitish oral mucous patches with a ‘snail-track' appearance surrounded by erythema localized on both the palatoglossal arch and the lower labial mucosa (Fig. 1). The patient had no lymphadenopathy, fever or skin alterations. Condylomata lata and maculopapular skin lesions were absent. Direct microscopic examination of the lesion revealed no hyphae. Direct immunofluorescence for Treponema pallidum (T. pallidum) from the mucous patches was positive (Fig. 2). Rapid plasma regain testing was positive at a titer of 1:16. In addition, a T. pallidum particle agglutination assay was reactive. A serologic test for infection with the human immunodeficiency virus was negative. A diagnosis of secondary syphilis-related oral lesion was made. The patient was treated with intramuscular penicillin with full resolution of the oral lesions within 2 weeks (Fig. 3). In secondary syphilis, oral manifestations can be present in one third to one half of all patients. Exanthema, especially when affecting the palms of the hands and soles of the feet and accompanying generalized lymphadenopathy, is highly suspicious. Oral lesions of secondary syphilis are typically multiple and symptomatic. Typical oral lesions in secondary syphilis tend to be divided into two subtypes: slightly elevated-type plaques and, occasionally, ulcerated, which are usually oval and covered with a gray or white pseudomembrane; or multiple mucous patches that may coalesce to give rise to serpiginous lesions, which is described as “snail-track ulcers”. The best way to diagnosis secondary syphilis-related oral lesion is based on a combination of the patient’s sexual/social history, a reasonable incubation period, clinical appearance, serological tests, and histological findings. Serologic testing remains the mainstay for diagnosis of syphilis as T. pallidum cannot be cultured in vitro. The traditional algorithm uses a non-treponemal serologic test for screening followed by a specific treponemal antigen serologic test for confirmation if the screening test is positive. Direct immunofluorescence for T. pallidum or direct fluorescent antibody techniques are also strongly suggested due to high sensitivity.