Background: Keratosis pilaris atrophicans defines a group of cutaneous disorders characterized by follicular hyperkeratosis and scarring. X-linked dominant inheritance has recently been reported in a Dutch family with a form of keratosis pilaris atrophicans defined as keratosis follicularis spinulosa decalvans, with males more severely affected and having corneal involvement. The clinical manifestations observed in different families by others and ourselves did not follow that pattern, suggesting genetic heterogeneity. We report our experience with 21 unrelated individuals.
Results: There were 15 male and six female patients whose onset of the skin disease was in early childhood but with scalp involvement occurring in the teen years. The cutaneous lesions consisted of follicular papules with scalp involvement present in eight individuals. Half the women had scalp involvement, and one female and one male had eye changes. Familial involvement was observed in three patients and was compatible with dominant inheritance. Histopathologic examination revealed hyperkeratosis of the upper follicle with an inflammatory response that resulted in follicular destruction. Response to therapy including keratolytics, antibiotics, corticosteroids and retinoids was limited.
Conclusions: Our findings support the hypothesis that there is genetic and clinical heterogeneity among the disorders represented by the term keratosis pilaris atrophicans. The cause of these diseases may be a disorder of the keratinocyte, which is responsible for inducing both the hyperkeratosis and inflammatory changes.