Systematic Review: Sweet Syndrome Associated with Inflammatory Bowel Disease

Sweet or Not? Azathioprine-Induced Sweet Syndrome Mimicking Erythema Nodosum in a Patient With Inflammatory Bowel Disease

This case report highlights the clinical challenge and need to distinguish Sweet syndrome and erythema nodosum (EN) in a 50-year-old woman with newly initiated azathioprine for inflammatory bowel disease. While she initially presented with clinical features concerning for drug-induced Sweet syndrome, a subsequent histopathological examination confirmed early-stage EN. Both Sweet syndrome and EN share common triggers and therapeutic responses, but have distinctive clinical characteristics. Subtle histologic differences also exist in lesion distribution and depth of infiltration. This case underscores the need for accurate differentiation in patients with inflammatory bowel disease to initiate appropriate management and avoid potential complications.

Sweet Syndrome Associated with Active Inflammatory Bowel Disease: A Case Series of a Rare Extra-intestinal Manifestation

BACKGROUND

Cutaneous extra-intestinal manifestations (EIM) occur in up to 20% of patients with IBD. Information about Sweet syndrome (SS)'s clinical course as a rare cutaneous EIM in IBD is limited to case reports. We present the largest retrospective cohort on the occurrence and management of SS in IBD.

STUDY

Electronic medical records and paper charts since 1980 were retrospectively reviewed at a large quaternary medical center to identify all adult IBD patients with histopathology-proven SS. Patient characteristics and clinical outcomes were evaluated.

RESULTS

25 IBD patients with SS were identified; 3 patients were assessed to have AZA-induced SS. The majority of SS patients were female. Median age at diagnosis was 47 years (IQR 33-54 years) and SS appeared at a median of 6.4 years after IBD diagnosis. IBD patients with SS had a high rate of complicated IBD phenotypes (75% extensive colitis in UC and 73% stricturing or penetrating disease in CD, with 100% colonic involvement), as well as frequent co-occurring EIMs (60%). SS correlated with global IBD disease activity. Corticosteroids were an effective therapy for SS in IBD. Recurrence rate of SS was 36%.

CONCLUSION

Contrary to previous case reports, SS was a cutaneous EIM occurring late after diagnosis of IBD in our cohort, with occurrences paralleling global IBD disease activity. Although AZA-induced and IBD-associated SS were both effectively treated with corticosteroids, distinguishing them is relevant for future IBD treatment strategies.

Ulcerative Colitis Concomitant with Cytomegalovirus Infection, Bullous Sweet's Syndrome, and Acute Myeloid Leukemia: A Case Report and Literature Review

Background

Ulcerative colitis (UC) is a chronic, relapsing progressive inflammatory immune disease. There is still no cure for it. Even worse, UC may predispose patients to opportunistic infections, and several extra-intestinal manifestations (EIMs) and comorbidities may antedate, occur with, or postdate the onset of UC, which may increase the mortality risk. But case reports of UC patients simultaneously concomitant with opportunistic infection, EIM, and comorbidity are extremely rare.

Case Presentation

We report a case of 51-year-old male patient with incipient UC accompanied by cytomegalovirus (CMV) infection and bullous Sweet's syndrome (bSS, a cutaneous EIM of UC) after treatment with oral mesalazine and prednisolone for 3 weeks. After clearance of the CMV infection by using ganciclovir, the patient was administered two cycles of infliximab to cure UC and bSS; however, he developed acute myeloid leukemia (AML) a month later and died after two cycles of chemotherapy.

Conclusion

Based on this rare case of UC concomitant with CMV infection, bSS and AML, we recommend that it is important to distinguish between an acute UC flare and opportunistic infections, especially in patients receiving immunosuppressive therapy, and monitor EIMs and comorbidities timely. Particular attention should be paid to cancer surveillance. Clinicians should be mindful of these facts to adopt optimal therapeutic options to address all aspects of UC. Early initiation of biological therapy may be of benefit to patients with newly diagnosed severe UC.

A novel murine model of pyoderma gangrenosum reveals that inflammatory skin-gut crosstalk is mediated by IL-1β-primed neutrophils

Pyoderma gangrenosum (PG) is a debilitating skin condition often accompanied by inflammatory bowel disease (IBD). Strikingly, ~40% of patients that present with PG have underlying IBD, suggesting shared but unknown mechanisms of pathogenesis. Impeding the development of effective treatments for PG is the absence of an animal model that exhibits features of both skin and gut manifestations. This study describes the development of the first experimental drug-induced mouse model of PG with concomitant intestinal inflammation. Topical application of pyrimidine synthesis inhibitors on wounded mouse skin generates skin ulcers enriched in neutrophil extracellular traps (NETs) as well as pro-inflammatory cellular and soluble mediators mimicking human PG. The mice also develop spontaneous intestinal inflammation demonstrated by histologic damage. Further investigations revealed increased circulating low density IL-1β primed neutrophils that undergo enhanced NETosis at inflamed tissue sites supported by an increase in circulatory citrullinated histone 3, a marker of aberrant NET formation. Granulocyte depletion dampens the intestinal inflammation in this model, further supporting the notion that granulocytes contribute to the skin-gut crosstalk in PG mice. We anticipate that this novel murine PG model will enable researchers to probe common disease mechanisms and identify more effective targets for treatment for PG patients with IBD.

Sweet syndrome and erythema nodosum in a young patient with ulcerative colitis

Sweet syndrome (SS) or acute febrile neutrophilic dermatosis is a rare inflammatory skin condition presenting as an abrupt onset of painful erythematous plaques or nodules, fever, and neutrophilia with histopathology showing a dense neutrophilic infiltrate. Systemic corticosteroids are the gold standard treatment for SS. We describe a case of a 26-year-old with a past medical history of ulcerative colitis on chronic prednisone presenting to the hospital with a 3-week ulcerative colitis flare with concomitant erythema nodosum and SS. While SS is well described, this inflammatory skin condition is uncommon in the setting of chronic anti-inflammatory medication.

Role of neutrophil interleukin-23 in spondyloarthropathy spectrum disorders

Neutrophilic inflammation is a pervasive characteristic common to spondyloarthropathies and related disorders. This inflammation manifests as Munro's microabscesses of the skin and osteoarticular neutrophilic inflammation in patients with psoriatic arthritis, intestinal crypt abscesses in patients with inflammatory bowel disease, ocular hypopyon in anterior uveitis, and neutrophilic macroscopic and microscopic inflammation in patients with Behçet's disease. Strong MHC class I associations are seen in these diseases, which represent so-called MHC-I-opathies, and these associations indicate an involvement of CD8 T-cell immunopathology that is not yet well understood. In this Personal View, we highlight emerging data suggesting that the T-cell-neutrophil axis involves both a T-cell-mediated and interleukin (IL)-17-mediated (type 17) recruitment and activation of neutrophils, and also a sequestration of activated neutrophils at disease sites that might directly amplify type 17 T-cell responses. This amplification likely involves neutrophilic production of IL-23 and proteases as well as other feedback mechanisms that could be regulated by local microbiota, pathogens, or tissue damage. This crosstalk between innate and adaptive immunity offers a novel explanation for how bacterial and fungal microbes at barrier sites could innately control type 17 T-cell development, with the aim of restoring tissue homoeostasis, and could potentially explain features of clinical disease and treatment response, such as the fast-onset action of the IL-23 pathway blockade in certain patients. This axis could be crucial to understanding non-response to IL-23 inhibitors among patients with ankylosing spondylitis, as the axial skeleton is a site rich in neutrophils and a site of haematopoiesis with myelopoiesis in adults.

New Practical Aspects of Sweet Syndrome

Sweet syndrome (SS), or acute febrile neutrophilic dermatosis, is an inflammatory, non-infectious skin reaction characterized clinically by tender, erythematous papules/plaques/pustules/nodules commonly appearing on the upper limbs, trunk, and head and neck; histologically, SS is characterized by dense neutrophilic infiltrate in the dermis. SS is accompanied by fever; an elevation of inflammatory markers (e.g., erythrocyte sedimentation rate, C reactive protein) in serum may also be observed. Although most cases of SS are idiopathic, SS also occurs in the setting of malignancy or following administration of an associated drug. SS has also been reported in association with pregnancy and a burgeoning list of infectious (most commonly upper respiratory tract infections) and inflammatory diseases; likewise, the litany of possible iatrogenic triggers has also grown. Over the past several years, a wider spectrum of SS presentation has been realized, with several reports highlighting novel clinical and histological variants. Corticosteroids continue to be efficacious first-line therapy for the majority of patients with SS, although novel steroid-sparing agents have been recently added to the therapeutic armamentarium against refractory SS. New mechanisms of SS induction have also been recognized, although the precise etiology of SS still remains elusive. Here, we catalogue the various clinical and histological presentations of SS, summarize recently reported disease associations and iatrogenic triggers, and review treatment options. We also attempt to frame the findings of this review in the context of established and emerging paradigms of SS pathogenesis.