An Uncommon Entity within the Keratosis

Folliculitis spinulosa decalvans is an uncommon condition characterized by follicular hyperkeratosis, followed by scarring alopecia. We report a 12-year-old boy affected by keratotic papules of the scalp and keratosis pilaris of the limbs who developed erythema, pustules, and scale crusts on the scalp associated with scarring alopecia. Histologic examina-tion showed follicular and interfollicular hyperkeratosis, follicular plugging, mild inflammation, and focal scarring. A transient remission of the inflam-matory changes on the scalp was obtained after treatment with isotretinoin. The follicular spinulous hyperkeratosis persisted. A severe relapse of the scalp inflammation was observed during a 2-year follow-up. Folliculitis spinulosa decalvans (FSD) is a term proposed in 1994 by Oranje et al (1) to identify a distinct clinical entity in the group of diseases with keratosis pilaris atro-phicans (KPA), characterized by persisting pustular ele-ments associated to typical keratotic papules of the scal