P040 An aggressive multisystem presentation of bowel-associated dermatosis–arthritis syndrome

Abstract

Bowel-associated dermatosis–arthritis syndrome (BADAS), also known as bowel-bypass syndrome, is a rare inflammatory condition associated with gastrointestinal bypass surgery and is thought to result from immune complex deposition. While BADAS classically presents with episodic arthritis and cutaneous eruptions, progression to severe multi-system disease is uncommon. We report the case of a 55-year-old woman who developed BADAS following a mini gastric bypass performed in 2021. Following her procedure, she developed an inflammatory arthritis fulfilling the criteria for rheumatoid arthritis, with no prior personal or family history of autoimmune disease. Treatment with adalimumab was complicated by recurrent sinusitis and eventual loss of efficacy. She subsequently developed widespread inflamed patches and plaques, with skin biopsy demonstrating a neutrophilic dermatosis initially consistent with Sweet syndrome. Her condition progressed to the development of painful bilateral lower-limb ulceration. Following further multidisciplinary team discussion, a diagnosis of pyoderma gangrenosum was made. Despite high-dose systemic corticosteroids, her response was poor. Further regional multidisciplinary review led to a unifying diagnosis of BADAS. She remains under joint care of rheumatology, dermatology and vascular surgery teams and has received extensive treatment including IVIg, infliximab, high-dose corticosteroids and hyperbaric therapy. Although her ulcers began to heal, recovery was complicated by recurrent skin infections and localized osteomyelitis of the right fourth toe. She is currently maintained on prednisolone 10 mg daily, mycophenolate mofetil and infliximab. This case demonstrates an unusually aggressive and progressive inflammatory disease course developing several years after gastric bypass surgery, associated with significant morbidity and a prolonged, complex clinical trajectory. It also underscores the potential for de novo autoimmune disease following bowel-bypass surgery in the absence of any personal or family history.