Pediatric cutaneous Crohn disease: A case series of 89 patients and review.

Background: Cutaneous (or "Metastatic") Crohn disease (CCD) is a rare and underrecognized disease characterized by cutaneous granulomatous inflammation. We describe patient demographics, clinical characteristics, histology, and treatment of 89 pediatric cases of CCD, including 78 previously reported and 11 new cases seen at four academic institutions. We emphasize the efficacy of biologic mono- and dual therapy.

Methods: PubMed identified cases using keywords including "metastatic Crohn disease" and "cutaneous Crohn disease". Patients were identified by retrospective review of the electronic health record including histopathologic diagnosis consistent with CCD. Chart review collected demographic, clinical, and histologic data.

Results: Most pediatric patients with CCD are male 55% (49/89), present with edema (73/89, 82%) and erythema (47/89, 53%) of the genitals (33/49, 67%), and have intestinal Crohn disease (69/89, 78%). Oral corticosteroids (53/75, 71%) and metronidazole (29/75, 39%) are the most frequently prescribed medications. Of the 17 patients treated with tumor necrosis factor (TNF)-blockade, 94% (16/17) had partial or total clearance. Ustekinumab resulted in clearance of cutaneous disease in two patients (2/3, 67%) and partial clearance in one patient (1/3, 33%). Two cases achieved total clearance with the use of dual biologic therapy defined as the use of two biologic therapies with differing mechanisms of action or the use of a biologic therapy and small molecule inhibitor.

Conclusions: TNF blockade is an effective treatment for pediatric CCD, and interleukin-12/23 inhibitors may be similarly effective. Consideration of dual biologic therapy may be useful in pediatric patients requiring discordant therapies for their intestinal and cutaneous CD.