Ustekinumab-induced Henoch-Schönlein purpura in Crohn’s disease: a case report and literature review

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Intest Res. 2026;24(1):177-181

Publication date (electronic) : 2025 November 14

doi : https://doi.org/10.5217/ir.2025.00009

Merih Deniz Toruner¹, Tugce Guvenir², Volkan Yilmaz², Ramazan Erdem Er², Murat Toruner^,2

¹Department of Gastroenterology, The Warren Alpert Medical School, Brown University, Providence, RI, USA

²Department of Gastroenterology, Ankara University Faculty of Medicine, Ankara, Türkiye

Correspondence to Murat Toruner, Department of Gastroenterology, Ankara University Faculty of Medicine, Hacettepe, A.Adnan Saygun Cd., Altindag, Ankara 06230, Türkiye. E-mail: toruner@medicine.ankara.edu.tr

Received 2025 January 22; Revised 2025 January 29; Accepted 2025 July 13.

Abstract

INTRODUCTION

Crohn’s disease is a progressive and chronic inflammatory disease under the umbrella of inflammatory bowel diseases (IBDs). The pathophysiology of Crohn’s disease is known to be multifactorial, with multiple players involving the intestinal epithelium, innate and adaptive immunity, and bacterial, fungal, and viral composition of the gut [1]. This complexity and the dysfunction of the immune system led to multiple treatment strategies heavily involving biological agents, tightly monitored and adjusted by the clinical team [2]. With widespread inflammation and gastrointestinal (GI) tract manifestations including chronic abdominal pain, diarrhea, intestinal ulcers, and bowel obstruction, Crohn’s disease also leads to extraintestinal manifestations in approximately 20% to 50% of the patient population [1,3]. The disease course and treatment plan are further complicated by extraintestinal manifestations, including dermatological manifestations, which can occur secondary to treatment, nutritional malabsorption, and reactive mucocutaneous manifestations relating to IBD [4]. Immunoglobulin A (IgA) vasculitis, previously known as Henoch-Schönlein purpura, has known associations with IBD, mainly after anti-tumor necrosis factor alpha (anti-TNF-α) reagents [5]. To the best of our knowledge, we are reporting the first ever case of IgA vasculitis after ustekinumab treatment, an interleukin (IL)-12 and IL-23 inhibitor [6], in Crohn’s disease. The patient provided written informed consent for data collection and for the reporting of the case and images.

CASE REPORT

A 20-year-old male Crohn’s disease patient (diagnosed in 2018) presented to the hospital with macular lesions in all extremities and the abdomen with no itching after the first dose of ustekinumab (Fig. 1).

Fig. 1.

Clinical photographs showing purpura. Purpura on the patient’s abdomen (A) and extremities (B-D).

The patient had a history of appendectomy and Crohn’s disease with ileocolonic involvement (Crohn’s Disease Activity Index: 370 and Simple Endoscopic Score-Crohn’s Disease: 20). His first endoscopic examinations revealed ulcerations in middle and distal esophagus and ulcerations in ileum, cecum, ascending colon, inflammatory polyps, millimetric ulcerations in descending colon, sigmoid colon, and rectum, with pathology showing mixed inflammation in lamina propria and focal cryptitis and crypt abscesses. The patient’s symptoms initially regressed with systemic steroid and azathioprine treatment for the first 4 years after diagnosis (until 2022). Follow-up endoscopic examinations revealed a normal esophagus with millimetric ulcerations in the duodenum and a narrowed ileocecal valve (ICV) with an ulcer and normal ileal and colonic mucosa. The patient was then transitioned to adult GI department. Upon progression of symptoms and newly developed abdominal pain, colonoscopy revealed countless deep ulcers in the ileum and linear ulcers in the colon segments. After this flare in 2022, the treatment regimen was changed from azathioprine monotherapy to infliximab monotherapy. The patient had a complete regression of symptoms until the fifth infusion. Following the increased clinical symptoms, patient had C-reactive protein (CRP) elevation, and the magnetic resonance enterography results showed ICV stenosis with a 4.5 cm segment with contrast enhancement and mural thickening in distal and terminal ileal segments, with end branches of neighboring mesenteric vessels (with Comb sign) (Fig. 2). At that time, the imaging tests and infectious diseases consultation revealed no other etiologies for high CRP other than Crohn’s disease activity.

Fig. 2.

Magnetic resonance enterography results of the patient. (A) Coronal image. (B) Axial image.

Following the flare, the patient was switched to ustekinumab treatment (with an induction dose of 520 mg intravenous [IV] infusion) and showed symptomatic and biochemical response to the ustekinumab treatment. However, 2 weeks after the induction dose, the patient presented with macular lesions in all his extremities and abdomen with no fever, abdominal pain, hematuria, and arthralgia (Fig. 1). He had an elevated white blood cell count (14.6 ×10⁹/L), elevated neutrophils (8.06×10⁹/L), normal hemoglobin (17.2 g/dL), elevated platelets (508 ×10⁹/L), elevated CRP (7.5 mg/dL) (CRP prior to ustekinumab 80 mg/dL), normal erythrocyte sedimentation rate (8 mm/hr), normal renal function tests, and normal liver function tests. Antinuclear antibody, antineutrophil cytoplasmic antibodies, anti-double-stranded DNA, anti-Saccharomyces cerevisiae, anti-β2GP1, C3, C4 were negative. Tissue transglutaminase was negative. Adenovirus, rotavirus, anti-hepatitis C virus antibody, hepatitis B surface antigen were negative, and anti hepatitis B surface antibody was positive. In addition to the dermatological symptoms, the urinalysis showed microscopic hematuria (1+) and proteinuria (1+). In pathology and immunofluorescence microscopy, there was mild perivascular dermatitis characterized by vasculopathy findings and IgA granular positivity in several blood vessel walls (Fig. 3). IgG, IgM, and C3 were negative. These findings were consistent with IgA vasculitis (Henoch-Schönlein purpura).

Fig. 3.

(A) In the papillary and upper reticular dermis, there is a focal, mild perivascular inflammatory cell infiltration predominantly composed of lymphocytes. Vascular endothelial cells appear reactive, and erythrocyte extravasation is present in the background (hematoxylin and eosin staining, ×22). (B) In the papillary dermis just beneath the epidermis, irregular immunoglobulin A (IgA) deposits are seen in the walls of two small vessels (direct immunofluorescence for IgA, ×75).

Ustekinumab was discontinued, and the patient was started on 80 mg prednisone, which was tapered off in 8 weeks. Cutaneous lesions disappeared. The patient was switched to adalimumab treatment. After 8 months, the patient had recurrent disease with nausea, vomiting, abdominal pain, CRP elevation, and was admitted. Magnetic resonance imaging scans showed perianal fistulizing disease with endoscopic active ileocolonic Crohn’s disease (Fig. 4). IV antibiotics were started, but as the symptoms persisted, IV methylprednisolone and IV vedolizumab were initiated (May 2023). With no response, after surgical consultation, right hemicolectomy and ileostomy were performed (June 2023).

Fig. 4.

Magnetic resonance imaging scan showing perianal fistulizing disease with endoscopic active ileocolonic Crohn’s disease.

Pathology showed severe colitis characterized by active ulcerations and granulomatous lymphadenitis consistent with Crohn’s disease. There was a continuation of microscopic inflammation at the proximal and distal surgical borders. Therefore, vedolizumab treatment was continued. During the follow-up visits, the patient gained weight and had a normal CRP. Ileoscopy and colonoscopy were performed and resulted in normal findings. He is currently being prepared for stoma closure under vedolizumab monotherapy.

DISCUSSION

The clinical and pathological presentation of the case was consistent with IgA vasculitis. IgA vasculitis (previously known as Henoch-Schönlein purpura), one of the most common forms of vasculitis in children, is a small vessel vasculitis with IgA-containing immune complex deposition, causing palpable purpura and various other symptoms including renal involvement [7]. Triggers of IgA vasculitis consist of external stimuli (microorganisms, including COVID-19), genetics, and potentially TNF and IL-17 inhibitors [8,9]. Treatment strategies for IgA vasculitis are heavily dependent on the presentation and the etiology, and may involve immunosuppressive therapy or plasmapheresis [7].

There are associations between IgA vasculitis and IBD, mainly dependent on the use of anti-TNF-α agents and regression with medication cessation and IBD treatment modification, though the exact association and pathogenesis remain unclear [5,10]. After the first article describing IBD-associated IgA vasculitis [11], several case studies show IgA vasculitis after the usage of medications including infliximab, adalimumab, vedolizumab, and cephalexin in Crohn’s disease patients [10,12-16]. For ustekinumab, there are case studies describing bullous pemphigoid for psoriasis treatment [17] and disseminated verrucosis in Crohn’s disease [18].

Cutaneous manifestations are commonly observed in patients with IBD, either as extraintestinal features of the underlying inflammatory process or as adverse effects of medical therapies, particularly immunosuppressive and biologic agents. These skin presentations span a broad clinical spectrum and can vary in timing, severity, and pathogenesis. Among the more common dermatologic manifestations are erythema nodosum, psoriasis, and aphthous ulcers, while less frequent but clinically significant conditions include various forms of vasculitis and neutrophilic dermatoses. Dermatologic manifestations in IBD affect more than 10% patients, with some estimates reporting even higher rates in Crohn’s disease compared to ulcerative colitis [4]. These manifestations include specific lesions, including metastatic Crohn’s disease, reactive conditions, and drug-induced reactions, particularly in patients receiving biological therapies [19]. This includes pyoderma gangrenosum, erythema nodosum, ulcers, specific lesions, drug rashes, purpura, vasculitis, psoriasis, and nutritional deficiency-related problems [20]. However, to the best of our knowledge, we are describing the first case of IgA vasculitis after ustekinumab treatment in Crohn’s disease. The patient had an elevated white blood cell, neutrophil, and platelet count with elevated CRP, hematuria, proteinuria, and normal liver and renal function tests. With perivascular dermatitis with IgA granular positivity, the patient’s findings were consistent with Henoch-Schönlein purpura. The patient was treated with prednisone, and ustekinumab was discontinued, with complete resolution of palpable purpura and cutaneous lesions and disappearance of hematuria and proteinuria. The clinical team is still following the patient for his Crohn’s disease.

The etiology of IgA vasculitis in IBD is not well understood, as every Crohn’s disease patient with dermatological manifestations, specifically vasculitis, can present in different ways with various triggers and disease presentations. Diagnosis and treatment should be done promptly, as it can lead to renal failure and other serious complications. As extraintestinal manifestations of Crohn’s complicate the treatment plan and prognosis of the patients, though this is a rare case, we recommend that physicians be aware of the presentation of IgA vasculitis and its treatment and alternative therapeutic strategies in IBD patients.

In conclusion, our case report showed a rare association between IgA vasculitis and ustekinumab in Crohn’s disease. The case was treated with switching to an out-of-class biologic and prednisone. Prompt diagnosis and treatment of IgA vasculitis, especially in IBD, is crucial to prevent adverse outcomes, but to better understand the association between IgA vasculitis, Ustekinumab, and Crohn’s disease, we recommend further research.

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