Alopecia that Leaves its Mark: A Case of Folliculitis Decalvans

Abstract

Folliculitis decalvans (FD) is a primary scarring alopecia of neutrophilic origin, characterized by chronic inflammation of the scalp that leads to permanent destruction of the hair follicle and its replacement by fibrous tissue. Clinically, it manifests as a central scarring alopecia plaque with active peripheral pustules, predominantly located on the vertex and parietal region. Its prevalence is estimated at 9% to 11.2% of all scarring alopecias, primarily affecting young men between 20 and 40 years of age. Although its exact pathogenesis remains uncertain, a multifactorial origin has been proposed, involving an altered immune response to Staphylococcus aureus and other bacteria, triggering sustained chronic inflammation that culminates in irreversible alopecia. The diagnosis is based on clinical and dermoscopic findings (such as the tufted hair sign) and is confirmed by scalp biopsy. Treatment remains challenging, with no standardized regimen; however, antibiotics, corticosteroids, and, more recently, biologic agents such as adalimumab have been proposed with promising results. We present the clinical case of a 16-year-old adolescent with lesions consistent with FD, highlighting aspects such as epidemiology, pathophysiology, clinical presentation, diagnosis, and treatment of this rare dermatological entity.

Recibido: 29/08/2025

Aprobado: 12/02/2026