Fournier’s gangrene in a patient with psoriatic arthritis: a case report

Resumo

Background: Fournier’s gangrene is a rare disease characterized by a perineal and abdominal necrotizing infection. The disease has an unfavorable prognosis without a prompt diagnosis and appropriate treatment. Objective: Present a Fournier’s gangrene case in a post-bariatric patient in a methotrexate treatment for psoriatic arthritis. Case presentation: 58-year-old man was admitted with seven days of anal pain and unresponsiveness to antibiotic therapy. His past medical history included bariatric surgery and psoriatic arthritis, which was treated with weekly 17.5 mg doses of methotrexate. During the examination, he presented left lateral perianal hyperemia down to the scrotum and a painful digital rectal examination. Laboratory tests indicated an intense infectious process. Computerized tomography confirmed the laboratory findings. Images showed perineal and perirectal adipose tissue densification, suggesting Fournier’s gangrene. The patient was submitted to perianal abscess drainage and debridement of necrotizing tissue. Perianal, gluteal, and left scrotum perineal regions were debrided. After that, the patient was referred to the ICU. Broad-spectrum antimicrobial therapy was administered. Clinical evolution was satisfactory, and the patient was discharged after 15 days. During home care, the patient developed pyelonephritis and COVID-19. Due to the patient’s immune status, methotrexate treatment was discontinued, and acitretin was prescribed. Conclusions: Fournier’s gangrene is a rare disease with an annual incidence of 1.6 cases per 100,000 males. Urogenital, anorectal, and genital skin infections in immunocompromised patients cause it. Early diagnosis is decisive for a good prognosis, considering the high mortality associated with the development of necrotizing fasciitis.