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 fistula of unknown origin (no proof of inflammatory bowel disease or any other underlying disease).

The clinical examination showed a painful peri-anal swelling without signs of underlying abscess.

After the first 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 canal (Figure A and B). No other lesions were found anywhere else on the patient’s body. In the context of the worldwide epidemic of monkeypox infection particularly among homosexual men, a smear of the perianal lesions was performed and sent for analysis. The rectosigmoidoscopy showed an unspecific proctitis and biopsy specimens where taken (Figure C).

What is the diagnosis?

See the Gastroenterology website (www.gastrojournal.org) for more information on submitting to Gastro Curbside Consult.

Answer to: Image 5: Monkeypox Infection

The analysis of the anal smear confirmed the infection with monkeypox virus and the histologic analysis of the rectal biopsy specimens showed unspecific proctitis.

The patient was informed about the diagnosis and the infectious risk. He was advised to remain in quarantine, to avoid contacts, and to allow contact tracing of his sexual partners. The symptoms completely disappeared after 3 weeks without any specific treatment.

The current case illustrates the clinical presentation of perianal monkeypox virus infection, and gastroenterologists should be aware of the proctologic manifestations of this emerging infectious disease. On the date of July 29, 2022, 5,189 cases were confirmed in the United States.¹

The virus is transmitted with body fluids and skin-on-skin contact, contact with respiratory secretions, unprotected sexual intercourse, or direct contact with monkeypox lesions. In a recent review, 98% on the infected patients were homosexual or bisexual men.²

The symptoms mainly include fever, which is followed by the appearance of multiple vesicular ulcerative lesions all over the body.² The particularity of the current case is the exclusive anal and perianal localization.

At the moment, there is no specific therapy validated for monkeypox virus infection. The management should focus on the treatment of symptoms and complications.³

Gottumukkala Subba Raju, Peush Sahni, and Sachin Wani, Section Editors