Psoriatic Alopecia in a Patient With Crohn Disease: An Uncommon Manifestation of Tumor Necrosis Factor α Inhibitors.

Tumor necrosis factor α (TNF-α) inhibitors are used to treat multiple inflammatory diseases including rheumatoid arthritis, inflammatory bowel disease, and psoriasis, among others. This family of medications can cause various side effects, some as common as injection-site reactions and others as rare as the paradoxical induction of psoriasiform skin lesions. Alopecic plaques recently have been described as an uncommon adverse effect of the TNF-α inhibitors adalimumab and infliximab. We present the case of a 12-year-old girl treated with adalimumab for Crohn disease who developed an alopecic crusted plaque on the scalp 6 months after increasing the dose of the medication. Biopsies, special stains, and sterile cultures yielded a diagnosis of psoriatic alopecia secondary to TNF-α inhibitor. A literature review for similar cases found 24 additional patients presenting with similar findings, of which only 6 were part of the pediatric population.