Vulvar Crohn's disease is a rare extraintestinal manifestation that may occur independently of intestinal activity and can closely mimic hidradenitis suppurativa (HS) 1. Cutaneous Crohn's disease includes contiguous perianal extension and metastatic Crohn, the latter defined by granulomatous inflammation at sites non-contiguous with the gastrointestinal tract 2. Vulvar involvement is uncommon and often under-recognized, presenting with edema, ulcerations, fissures, nodules, and fistulas. HS, in contrast, is a chronic inflammatory disorder of intertriginous areas, characterized by painful nodules, abscesses, sinus tracts, and scarring, and is diagnosed clinically based on morphology, distribution, and chronicity of the lesions 3. Distinguishing vulvar Crohn's disease from HS is particularly challenging due to overlapping clinical features. A high index of suspicion is therefore essential to ensure appropriate diagnosis and management. We report a case of vulvar Crohn's disease initially misdiagnosed as severe HS in a patient with quiescent intestinal disease. A 33-year-old woman with ileocolonic Crohn's disease diagnosed at age 14, in sustained remission for five years on adalimumab 40 mg biweekly, presented with a one-year history of worsening genital lesions. Although she had a history of perianal Crohn's disease, no active anorectal involvement was present at evaluation, and the intestinal disease was in sustained clinical, endoscopic, and biochemical remission. Dermatological examination revealed vegetative plaques and serpiginous ulcerations involving the vulva and perineal folds, associated with marked edema and draining fistulous tracts exuding blood and purulent material (Figure 1). The lesions were severely painful, causing dyspareunia and significant impairment of quality of life. No involvement of other typical HS sites, such as axillary or inframammary areas, was observed. Based on clinical findings, the patient had previously been diagnosed with Hurley stage III HS and treated with multiple courses of systemic antibiotics without improvement. Given the atypical isolated genital involvement and lack of therapeutic response, a skin biopsy from vulvar and perianal areas was performed. Histopathology showed acanthosis and papillomatosis with dermal fibrosis and aggregates of CD68-positive histiocytes forming non-necrotizing granulomas with multinucleated Langhans-type giant cells (Figure 2). No viral cytopathic changes or vasculitis were detected, and special stains (Periodic acid-Schiff PAS, Grocott, and Ziehl-Neelsen) were negative for microorganisms. These findings supported a diagnosis of non-infectious granulomatous dermatitis consistent with vulvar Crohn's disease. Following diagnosis, adalimumab was discontinued and ustekinumab initiated with weight-based intravenous induction followed by 90 mg subcutaneously every 8 weeks, in line with approved Crohn's disease regimens and emerging evidence in vulvar involvement 1. However, clinical response remained limited. Differentiating vulvar Crohn's disease from HS remains difficult due to their clinical overlap. This is further complicated in patients with inflammatory bowel disease (IBD), in whom HS is a recognized comorbidity, particularly in Crohn's disease 3. Certain features may raise suspicion for vulvar Crohn's disease, including marked vulvar edema, serpiginous or “knife-cut” ulcerations, absence of lesions in other typical HS sites, and poor response to standard HS treatments 4. In our case, isolated genital involvement and antibiotic failure prompted histological reassessment. Another challenge was the discordance between intestinal and cutaneous disease activity. Extraintestinal manifestations may infact occur independently of intestinal inflammation, making reliance solely on bowel activity potentially misleading 5. Vulvar Crohn's disease remains difficult to manage, with no standardized guidelines and often suboptimal responses. Management frequently requires switching or optimizing biologic therapy, adjunctive treatments, and occasionally surgery, highlighting the need for a multidisciplinary approach 1. This case emphasizes the importance of maintaining a high index of suspicion when evaluating HS-like lesions in patients with IBD. Early histopathological assessment should be considered in patients with Crohn's disease presenting with atypical, isolated genital lesions or poor response to HS therapies, to enable timely diagnosis, guide treatment, and prevent delays that may significantly impact quality of life. The authors have nothing to report. A.V.M. reports consultancy/advisory boards disease-relevant honoraria from AbbVie, Amgen, Boehringer-Ingelheim, Bristol Myers Squibb, Incyte, Leopharma, Novartis, Pfizer, Sanofi, and UCB. Consent for the publication of recognizable patient photographs or other identifiable material was obtained. The patient gave consent with the understanding that this information may be publicly available. The authors declare no conflicts of interest. The data that support the findings of this study are available from the corresponding author upon reasonable request.
Termini et al. (Wed,) studied this question.