Follicular Granular Parakeratosis of the Face and Neck.

Granular parakeratosis (GP) is a rare disorder of keratinization characterized by the retention of keratohyalin granules within the stratum corneum. Originally described as solely involving the axillae (previously known as axillary granular parakeratosis), GP is now recognized to involve other intertriginous areas, including the inframammary folds, abdominal folds, groin, and neck. Follicular granular parakeratosis (FGP) represents an exceedingly rare variant in which the pathologic process involves the follicular infundibulum. We report a case of both follicular and inter follicular GP in a 47-year-old woman presenting with a chronic pruritic eruption on the face, anterior neck, and chest-a distribution distinct from the typical GP distribution. Histopathologic examination revealed prominent keratohyalin granules within the stratum corneum and follicular infundibulum, with multiple mounded areas of granular parakeratosis, establishing the diagnosis of FGP. To our knowledge, only three prior cases of FGP have been reported in the literature, making this a remarkably rare presentation. This case emphasizes the importance of recognizing follicular involvement in GP as a distinct clinicopathologic pattern that differs from classic GP in both location and histology.