Case report

We report the case of a 48 year-old male, with no medical history of interest, who presented with a two month history of rectal bleeding and tenesmus. He presented a papular erythematous rash on the trunk and extremities, macules on the soles of the feet and axillary and inguinal lymph nodes. The liver tests were abnormal. Serological tests for syphilis were positive and the human immunodeficiency virus (HIV) test was negative. Colonoscopy identified irregular and long rectal ulcers at the postanal level. Biopsies were taken from the ulcer and identified an acute inflammatory cell infiltration and the staining for spirochetes was positive. The patient underwent treatment with intramuscular benzyl-penicillin (Benzetacyl(r)), with a complete resolution of the infection.

Fig. 1 Endoscopic image: the rectal area is affected at the postanal level with long and serpiginous ulcers that occupy half of the light, with erythematous and edematous surrounding mucosa. 

Discussion

Syphilis is a chronic infectious disease caused by the Treponema pallidum bacteria. Secondary syphilis is a systemic disease and occurs in around 25% of cases with primary syphilis without treatment, some weeks or months later. In some cases, the primary lesion is not detected ². Patients with secondary syphilis usually present with systemic signs, often non-specific. Thus, it is difficult to diagnose, and clinical suspicion is crucial ². The patient reported here presented with a cutaneous rash, proctitis, hepatitis and adenopathies, which may present with the disease. The serological tests and biopsy were compatible with secondary syphilis. The endoscopic findings were similar to other several diseases such as inflammatory bowel disease (IBD), a viral infection, lymphoma, other tumors and a solitary rectal ulcer. Therefore, syphilis must be included in the differential diagnosis of anorectal ulcers ^3,4,5.