Differential diagnosis of inflammatory bowel disease is often very challenging. Paracoccidioidomycosis is a fungal disease that can mimic manifestations of Crohn's disease.
We report a case of a 13-year-old Caucasian boy with abdominal pain for 1.5 years associated with nausea, diarrhea, and weight loss of 10 kg. He presented increased C-reactive protein and an increased erythrocyte sedimentation rate. A colonoscopy showed deep serpiginous ulcers throughout his entire colon and rectum, which suggested Crohn's disease. He received one dose of infliximab, which is an anti-tumor necrosis factor-α, and showed no improvement. After the second dose, he got worse and started to have bloody diarrhea. A new colonoscopy was performed and pathological examination revealed ulcerative chronic inflammation with non-caseating granulomas and fungal structures (budding forms) compatible with Paracoccidioides brasiliensis. He underwent intravenously administered and then orally administered trimethoprim-sulfamethoxazole treatment. Due to drug intolerance, he was treated with amphotericin B and itraconazole, then he showed clinical improvement and mucosal healing with good outcome.
Paracoccidioidomycosis must be part of the differential diagnosis of inflammatory bowel diseases in endemic areas and must be excluded before starting immunosuppressive therapy.