S4844 Cutaneous Clues to Colitis: Sweet’s Syndrome as the Initial Manifestation of Ulcerative Colitis

Introduction: Sweet syndrome or neutrophilic dermatosis is a rare condition characterized by sudden onset of tender erythematous plaques or nodules with pathologic evidence of dense neutrophilic infiltration. Although rare, it has been associated with inflammatory bowel disease. This is a case of classic Sweet’s syndrome (CSS) as an initial manifestation of ulcerative colitis. Case Description/Methods: Twenty-year-old man presented with painful, erythematous, non-healing ulceration on bilateral lower extremities and migratory polyarthralgia for about 5 months. Punch biopsy of skin from lower leg showed organizing granulation tissue, fibrosis, and perivascular inflammation. Labs noted for ANA 1:80 speckled, p-ANCA positive, and rest autoimmune workup negative. He returned to emergency department about 15 days later with epigastric pain and Tmax of 102 F. Elevated C-reactive protein and erythrocyte sedimentation rate noted. Computed tomography abdomen/pelvis showed necrotic lymph nodes adjacent to the cecum and mild cecal wall thickening with concerns for typhlitis. Magnetic resonance angiography abdomen/pelvis was negative for vasculitis. Punch biopsy from right hip and left ankle demonstrated hyperplastic epithelium with dermal edema and diffuse mixed suppurative and lymphoplasmacytic inflammation consistent with Sweet’s syndrome. Patient recalled that he had intermittent rectal bleeding that would self-resolve for several years. Fecal calprotectin elevated at 213 mcg/g. Colonoscopy showed localized inflammation on the distal 2-3 cm of the rectum from the anal verge. Colonic biopsy negative for microscopic colitis and rectal biopsy positive for active proctitis with focal cyptitis. Currently patient is on adalimumab, methotrexate, and prednisone with significant improvement of his lesions and arthralgias. Discussion: Sweet’s syndrome consists mostly of CSS. It is a rare manifestation in patients with inflammatory bowel disease. The woman-to-man ratio is 4 to 1 and age of onset is between 30 and 60. Exact pathogenesis is unknown; theories include hypersensitivity reactions that may trigger neutrophil activation and infiltration. CSS can be mistaken for vasculitis, infection, or pyoderma gangrenosum, resulting in delayed diagnosis. Our case highlights that thorough evaluation of autoimmune disorders with painful lesions and consideration for prompt endoscopy is imperative to prevent misdiagnosis and delayed care.