Prurigo nodularis is a challenging problem to treat. It manifests as nodules in the skin, secondary to chronic scratching, and underlying pruritus (itch). Prurigo nodularis has been treated with a wide range of medications and treatments, including topical steroids, antihistamines, mirtazapine, gabapentin, phototherapy, and cyclosporine with variable results. Two recent case study reports indicate that dupilumab may be helpful for prurigo nodularis.
A recent case series of three patients raises the interesting possibility of prurigo nodularis being treatable with dupilumab. Dupilumab is an IL-4 receptor inhibitor, and a novel treatment for atopic dermatitis. In this small case series, all three patients had a decrease in itch, a reduction in the size and number of prurigo nodularis lesions, and were able to reduce or discontinue one or more other therapies. Another series of four cases by different authors similarly showed a decrease in itch in prurigo nodularis patients with the use of dupilumab.
It is not certain how dupilumab works on prurigo nodularis, but it is possible that prurigo nodularis is a manifestation of an underlying atopic dermatitis. Alternatively, by blocking the effects of IL-4 and IL-13, dupilumab it may interrupt interactions in the skin that are part of the itch pathways.
Further studies are necessary, but dupilumab may be a useful treatment for patients with prurigo nodularis refractory to other treatments.
Mollanazar NK, Elgash M, Weaver L, Valdes-Rodriguez R, Hsu S. Reduced Itch Associated With Dupilumab Treatment In 4 Patients With Prurigo Nodularis. JAMA Dermatol. 2019;155(1):121–122. doi:10.1001/jamadermatol.2018.3906