Severe Psoriasis Leading to Scarring Alopecia of the Scalp Responding to Biologic Therapy

Abstract

Scalp psoriasis affects the majority of patients with psoriasis and can cause disproportionate pruritus, pain, and psychosocial burden. While most cases respond to topical therapies and/or systemic agents, progression to scarring alopecia is rare and remains poorly described, with limited guidance on optimal management. We report a 36-year-old woman with psoriasis and psoriatic arthritis who developed severe, recalcitrant scalp psoriasis with progressive hair loss despite sequential systemic therapies over four years, in addition to adjunctive scalp-directed treatments. After a two-year lapse in care during which she was off all therapies, she re-presented with psoriasis involving thick vertex scalp plaques with micaceous scale and patches of complete alopecia with scarring. Bimekizumab 320 mg every 4 weeks was initiated, followed by development of a generalized pruritic eruption consistent with bimekizumab-associated eczema that was managed with adjunct dupilumab. Over the following months, scalp erythema and scaling progressively improved and hair density increased, permitting transition to maintenance dosing every 8 weeks, when disease recurred and again improved after escalation back to every-4-week dosing. To our knowledge, this is the first report of psoriatic scarring alopecia improving with bimekizumab, suggesting that dual IL-17A/IL-17F blockade may be beneficial in this rare, refractory phenotype and warrants further study.