An Unusual Cause of Anal Pain

Question: We report the case of a 30-year-old man who presented twice to the emergency room for anal pain. There were no other symptoms and, particularly, no diarrhea, nor fever. The patient declared to have regular anal sexual intercourse with other men. In his medical history were 2 surgeries in 2010 and 2018 for anal fi stula of unknown origin (no proof of in fl ammatory bowel disease or any other underlying disease). Theclinical examination showed a painful peri-anal swelling without signs of underlying abscess. After the fi rst visit, an infection with Neisseria gonorrhea was diagnosed based on the positive polymerase chain reaction of the anal swab. He was treated with an intramuscular injection of Ceftriaxone 500 mg and Azithromycine 1 g once orally. Despite the treatment, he presented again 2 weeks later to the emergency room with worsening of anal pain. Clinical examination only showed a painful swelling of the anus. Blood analysis showed elevated C-reactive protein of 26.4 mg/L (normal < 5 mg/L) with normal white blood cells count. A pelvic computed tomography scan was performed to rule out a perianal abscess. A repeat anal swab was negative for Neisseria gonorrhea and Chlamydia trachomatis . The patient was discharged from the emergency room with stronger painkillers. We saw the patient 3 days later and the symptoms were still present. No fever was reported. At the anal examination we noticed several white elevated crater-like lesions with central depression; these were very painful to touch in and around the anal