Chronological clinicopathological characterization of rapidly progressive alopecia areata resistant to multiple i.v. corticosteroid pulse therapies: An implication for improving the efficacy

Intravenous corticosteroid pulse therapy (pulse therapy) has been reported to be effective for rapidly progressive alopecia areata ( RP ‐ AA ). Mostly, a single 3‐day administration of corticosteroid (methylprednisolone 500 mg/day) has been performed in Japan; however, to what extent additional administrations improve the outcome has not been fully elucidated. To assess the advantage of repeating the pulse therapy to RP ‐ AA cases refractory to the initial intervention, retrospective clinicopathological analysis was performed. Detailed chronological analysis was conducted in eight cases (one man and seven women; average age, 38.3 ± 10.4 years) demonstrating total scalp hair loss 3 months after the first pulse therapy and treated with additional rounds of the pulse therapy. All cases manifested total hair loss, scalp edema, itch or pain on the scalp after the initial intervention. Histopathological analyses of affected lesions prior to additional pulse therapies revealed persisting dense perifollicular lymphocytic inflammation in all cases. Interestingly, such inflammatory change tended to be severer when compared with previously reported pulse therapy good responders. Extra pulse therapy resulted in partial regrowth of terminal hairs in three out of eight cases, but all of them experienced relapse in the long run. The literature review also suggested limited efficacy of repeating pulse therapy to severe AA cases. These findings suggested that the efficacy of currently conducted repetitive pulse therapy is limited in RP ‐ AA cases with extensive perifollicular inflammation and resistant to the initial pulse therapy. Modulation of the dose and the interval of intervention, in combination with alternative approaches, may be required to achieve a successful outcome.