Axonal sensorimotor polyneuropathy after starting guselkumab

Guselkumab is an IL-23 inhibitor that binds to the p19 subunit of IL-23 that is highly efficacious and well tolerated for the treatment of moderate-to-severe plaque psoriasis. We report a 20-year-old male who developed sensorimotor axonal polyneuropathy starting treatment with guselkumab, confirmed by neurological examination and serial neurophysiologic studies. His symptoms improved within 5 months of stopping the treatment. The neurophysiologic studies also showed improvement but with continued neuropathy and re-innervation changes on electromyography after about 10 months of stopping treatment. The time line of symptoms and a positive de-challenge are strong but not definitive evidence of guselkumab as a cause.