INTRODUCTION: Sweet's Syndrome is characterized by fever, neutrophilia, painful erythematous skin lesions (papules, nodules, plaques) and a diffuse neutrophilic infiltrate in the upper dermis of the skin. It can be idiopathic, malignancy-associated or drug-induced. CASE REPORT: A 47 year old female with Ulcerative Colitis presented with 3 days of nausea, vomiting and diarrhea. She was receiving Azathioprine 100mg daily for 3 years. Laboratory studies were significant for WBC 18.4 (89% neutrophils), ESR 20, CRP 14. Stool cultures and clostridium difficile toxin were negative. CT scan showed diffuse colonic, gastric antral and duodenal wall thickening. Upper endoscopy revealed diffuse gastric erythema, and shallow duodenal ulcerations (pathology showing acute and chronic duodenitis). Flexible sigmoidoscopy showed confluent ulcerations and mucus exudates in the recto-sigmoid colon (pathology showing chronic active colitis). 3 days after admission, she developed high grade fevers (1020 F), and new erythematous tender papules on the torso and extremities. Biopsy of the papules showed interstitial neutrophilic infiltrate in the upper dermis consistent with Sweet's Syndrome. She declined steroid therapy due to a prior adverse reaction of elevated intraocular pressures, but agreed to treatment with Infliximab at a dose of 5mg/kg. Her skin lesions and fever resolved within 2 days, and she had improvement of her gastrointestinal complaints. She was discharged, continued on outpatient Infliximab therapy and is currently in clinical remission. DISCUSSION: We report a case of Sweet's Syndrome in a patient with inflammatory bowel disease (IBD) successfully treated with Infliximab. Sweet's Syndrome is a rare extra-intestinal manifestation of IBD, presenting independent of its activity and should be considered in the differential diagnosis of a patient with IBD who develops skin lesions. The skin manifestations can last for weeks to months without treatment. Systemic corticosteroids are the gold standard therapy. The success of Infliximab in our patient's treatment supports the role of tumor necrosis factor (TNF) in the pathogenesis of Sweet's Syndrome. Few case reports have shown the treatment of Sweet's Syndrome associated with IBD with infliximab at doses of 5mg/kg and 10mg/kg. Our case suggests that Infliximab and other anti-TNF agents can be successfully used as a second line therapy for Sweet's Syndrome in those with IBD.Figure 1Figure 2