Most patients with cutaneous Crohn disease—a rare granulomatous skin manifestation discontinuous from the gastrointestinal tract—who received biologic or small-molecule inhibitor therapy had documented partial or complete improvement at last dermatology follow-up, according to a retrospective multicenter study. However, the uncontrolled design and frequent use of combination therapy preclude conclusions about treatment efficacy or optimal timing.
Researchers reviewed electronic health record data from nine US academic centers and identified 57 pediatric and adult patients with cutaneous Crohn disease (CCD) who had at least 1 dermatology visit between 2000 and 2020. Diagnosis required clinical and histopathologic findings consistent with Delphi consensus criteria. Outcomes at last dermatology follow-up were categorized as complete clearance, partial clearance, no effect, or worsening based on clinical documentation.
Among the cohort, 81% of patients were female, and 70% had intestinal Crohn disease at the time of CCD diagnosis. The mean age at diagnosis was 37 years, with an age range of 10 to 57 years. The terminal ileum was the most commonly involved gastrointestinal site. Additionally, 23% of patients had no inflammatory bowel disease diagnosis, while 5% had ulcerative colitis and 2% had indeterminate colitis.
Genital involvement was the most common cutaneous presentation, reported in 44% of patients, including vulvar disease in 40%. Ulcerations occurred in 42% of patients, followed by edema in 32% and fissures in 25%.
Biologic or small-molecule inhibitor therapy was used in 47 patients (82%). Tumor necrosis factor alpha inhibitors were the most commonly prescribed agents, used in 85% of treated patients. Ustekinumab was used in 53% of treated patients, including 8 patients who also received vedolizumab for intestinal disease. Smaller numbers of patients received risankizumab, upadacitinib, or tofacitinib.
Among patients who initiated biologic or small-molecule inhibitor therapy prior to CCD diagnosis, 26 patients (90%) demonstrated partial or complete resolution at last dermatology follow-up compared with 10 patients (71%) who initiated therapy following diagnosis. However, the study was not designed to evaluate treatment timing, and patients treated prior to CCD diagnosis were often already receiving therapy for intestinal Crohn disease, limiting causal interpretation of the comparison.
Single-agent biologic or small-molecule inhibitor therapy was uncommon. At last follow-up, fewer than half of treated patients remained on a single biologic or small-molecule inhibitor. Most patients also received nonbiologic systemic medications such as corticosteroids, antibiotics, methotrexate, tacrolimus, or aminosalicylates, and dose escalation was frequently reported for intestinal or cutaneous disease control.
The researchers noted that the study was limited by its retrospective design and heterogeneous data collection across institutions. Outcomes were derived from clinical documentation rather than standardized disease activity measures, and treatment regimens varied substantially across patients and centers.
"This multi-institutional study adds to the limited literature on [cutaneous Crohn disease]," wrote lead study author Grace E. McKay, MD, of the University of Wisconsin School of Medicine and Public Health, Madison, and colleagues.
Disclosures can be found in the published research letter.
Source: JAMA Dermatology
