Bowel-Associated Dermatosis-Arthritis Syndrome: A Report of a Rare Case.

A 31-year-old female, recently discharged after improvement of an exacerbation of ulcerative colitis, returned to the hospital due to fever, polyarthralgia affecting the knees and ankles, and symmetric violaceous papulopustular lesions on her arms, trunk, and lower limbs. Histological examination revealed superficial dermal edema and perivascular invasion of neutrophils with leukocytoclasia, consistent with neutrophilic dermatosis, and a diagnosis of bowel-associated dermatosis-arthritis syndrome (BADAS) was established. BADAS is a rare, characteristic neutrophilic dermatosis and arthritis mainly associated with intestinal inflammatory disease due to bacterial overgrowthand subsequent immune complex formation and deposition. Treatment involves a combination of antibiotic therapy and immunosuppression, and prognosis is linked to improvement of the underlying condition.