Successful Treatment of Refractory Palmoplantar Pustulosis With Bimekizumab in a Patient With Multiple Sclerosis: A Case Report

We present a case of refractory palmoplantar pustulosis (PPP) in a female in her early 50s with a history of well-controlled multiple sclerosis (MS). PPP is a dermatological condition characterized by chronic pustules often accompanied by fissures on the palms of the hands or soles of the feet. It is often seen in association with psoriasis vulgaris and arthritis; however, it can also present as isolated lesions. Although several treatment options exist for PPP, including topical corticosteroids, topical calcineurin inhibitors, vitamin D analogs, narrowband ultraviolet B (NBUVB) phototherapy, biologics, and topical retinoids, PPP remains a complex disease to treat. In this case, the patient failed to achieve significant improvement despite trialing multiple therapies, including topical corticosteroids, topical agents, systemic therapy, NBUVB phototherapy, and several biologics, as well as adjunctive antifungal therapy, with persistent pain secondary to fissuring and scaling of her plantar skin. Due to the refractory nature of her PPP, bimekizumab, an anti-IL-17A and IL-17F antibody therapy, was administered as a subcutaneous injection at weeks 0, 4, 8, 12, and 16, followed by maintenance dosing every eight weeks. The patient experienced a significant and sustained improvement in her PPP. Although bimekizumab is primarily used to treat psoriasis and psoriatic arthritis, this case highlights its potential role in the treatment of refractory PPP. There are concerns regarding the safety of biologic treatment in patients with MS due to the possibility of worsening MS symptoms. However, these concerns are primarily associated with anti-tumor necrosis factor therapies and may not be directly applicable to IL-17 inhibitors such as bimekizumab. This clinical case suggests that bimekizumab may be a reasonable therapeutic option in patients with well-controlled MS, though further studies are needed to better characterize its safety in this population.