INTRODUCTION: Sweet syndrome (SS) is an inflammatory skin disorder that has been frequently reported in patients with inflammatory bowel disease (IBD). It is unclear whether this disease affects patients with Crohn’s disease (CD) or ulcerative colitis (UC) differently. We performed a systematic review of reported cases of SS in patients with IBD to assess demographic and clinical differences among patients with CD and UC. METHODS: We searched Medline, Embase, Cochrane Central, and Web of Science from inception through March 2020 for non-abstract publications describing SS in adult patients with IBD with English as a language restriction. The studies were screened by two independent reviewers who then extracted the study data. A skin biopsy was required for the diagnosis of SS. The data was analyzed using Fisher exact, Chi-square, and Mann-Whitney U tests. RESULTS: A total of 91 cases were included in the analysis and are summarized in Tables 1–3. Although the median age of occurrence of SS in patients with CD and UC was similar and around 42 years, a higher number of females were reported in CD (72.9%) compared to UC (44.2%). In UC, about 16% of patients were Asian, while no CD patients were Asian. Interestingly, while SS occurred most commonly after the diagnosis of IBD, patients with CD tend to develop SS earlier in the disease course compared to UC. Clinical characteristics of SS did not differ between UC and CD, with both most commonly presenting as multiple maculopapular, plaque-like, or pustular lesions on the extremities or trunk (Table 2). As compared to UC, patients with CD reported abdominal pain more frequently at the time of SS occurrence (11.63% vs 37.5% respectively). SS was associated equally with active IBD in both groups, and other extraintestinal manifestations were common in both. Interestingly, a concomitant history of pyoderma gangrenosum (PG) was only noted in patients with UC. CONCLUSION: Sweet Syndrome is considered an extraintestinal manifestation of IBD, and it may occur as a heralding sign to IBD in 25-30% of cases. The differences in sex, ethnicity, and timing of SS between patients of CD and UC are difficult to explain and may be related to the limited number of cases reported in the literature. Abdominal pain and PG frequency, on the other hand, may be true differences known to occur in CD and UC patients, respectively.Table 1.: Demographics of SS patients and the temporal relation of SS to IBDTable 2.: Clinical Characteristics and treatment of SSTable 3.: Characteristics of IBD at the time of SS occurrence