Novelty in the gut: a review of the gastrointestinal manifestations of syphilis

Syphilis is a systemic infection caused by the spirochete Treponema pallidum. It is transmitted during pregnancy or through sexual contact. Signs and symptoms vary depending on the clinical stage of the disease. Syphilis has been well-studied, and the introduction of penicillin has resulted in a decline in the number of new cases and deaths. Recently, however, there has been a surge in new cases in young people, especially those with human immunodeficiency virus (HIV). This epidemiological shift has been attributed to increased sexual activity, risky sexual behaviors, and immunodeficiency. There is a paucity of data on gastrointestinal (GI) manifestations of syphilis owing to its rarity and lack of physician awareness. T. pallidum can seed to any part of the GI tract, resulting in esophagitis, gastritis, hepatitis, pancreatitis, or proctocolitis. Depending on the affected part of the GI tract, syphilis can present with nausea, vomiting, painless esophageal ulcers, dysphagia, abdominal pain, weight loss due to early satiety, diarrhea, melena, hematochezia, dyschezia, or anorectal ulcers. Given its indolent clinical course and vague presentation, GI syphilis can mimic other GI disorders, which can delay diagnosis and treatment. A detailed medical history, physical examination, serological tests, and endoscopy can provide a definitive diagnosis. Syphilis and its GI complications are usually treated with long-acting intramuscular penicillin benzathine, and rarely with a 14-day course of intravenous penicillin. Herein, we describe the clinical features, etiopathogenesis, diagnosis, and treatment of GI syphilis. This primer should aid clinicians in timely diagnosis and treatment of various presentations of GI syphilis.