Sweet's syndrome and fistulizing Crohn's disease: A case report

Sweet Syndrome Associated With Crohn’s Disease Developed After a Combo Therapy With Infliximab and Azathioprine: A Case Report

Sweet syndrome, also known as Acute Febrile Neutrophilic Dermatosis, is a rare inflammatory condition. The exact pathogenesis of Sweet syndrome is unclear, however, autoimmune and inflammatory conditions including inflammatory bowel disease have been linked as underlying etiologies. Since its description, in 1964, there have been published less than fifty reports of Crohn’s-associated Sweet syndrome.

We report a 43-year-old male patient with a medical history of Crohn’s disease who subsequently developed Sweet syndrome. Two years after the diagnosis of Crohn’s disease the patient was administered a combo therapy with Infliximab and Azathioprine followed by deep remission. A few months later the patient manifested with skin lesions with histopathological findings suggestive of Sweet syndrome.

Sweet syndrome, although rare, may occur as an extra-intestinal manifestation of Crohn’s disease. This report illustrates the need for a thorough investigation of patients with Crohn’s disease presenting with skin lesions. We hope it will add to the current literature and help understand this rare phenomenon in order to achieve a proper diagnosis.

Systematic Review: Sweet Syndrome Associated with Inflammatory Bowel Disease

BACKGROUND AND AIMS

Sweet syndrome [SS] is a dermatological condition associated with both inflammatory bowel disease [IBD] and azathioprine use. We performed a systematic review to better delineate clinical characteristics and outcomes of SS in IBD patients.

METHODS

Peer-reviewed, full-text journal publications from inception to April 2020 in English language and adult subjects with IBD were included. Skin biopsy was required as SS gold-standard diagnosis. Azathioprine-associated SS required recent azathioprine introduction or recurrence of SS after azathioprine re-challenge.

RESULTS

We included 89 publications with 95 patients [mean age of SS diagnosis: 44 years; 59% female; 20 with azathioprine-associated SS and 75 without]. SS was diagnosed prior to IBD in 5.3%, at time of IBD diagnosis in 29.5% and after diagnosis in 64.2%. In total, 91% of patients with SS had known colonic involvement and the majority [76%] had active IBD at diagnosis; 22% had additional extra-intestinal manifestations. Successful therapies for SS included corticosteroids [90.5%], anti-tumour necrosis factor [TNF]-α inhibitor therapy [14.8%] and azathioprine [11.6%]. Azathioprine-associated SS was distinct, with 85% male patients, mean age of SS diagnosis of 50 years and a lower likelihood to be prescribed corticosteroids for treatment [75% vs 94.7% of non-azathioprine-associated SS, p = 0.008]. All patients with azathioprine-associated SS improved with medication cessation and developed recurrence after re-challenge.

CONCLUSIONS

SS may precede or occur with IBD diagnosis in almost one-third of cases. Azathioprine and IBD-associated SS present and behave distinctly, especially with regard to gender, age at diagnosis and recurrence risk. Corticosteroids and TNF-α inhibitors have demonstrated efficacy in treating SS in IBD.