Infantile granular parakeratosis: recognition of two clinical patterns

Granular parakeratosis is an acquired, idiopathic disorder of keratinization typified by retention hyperkeratosis. It usually occurs in women at intertriginous sites. There have been only 2 reports of infants with granular parakeratosis to our knowledge. We describe 3 additional infants with granular parakeratosis. We demonstrate that infantile granular parakeratosis exhibits 2 clinical patterns: bilateral linear plaques in the inguinal folds; and erythematous geometric plaques underlying pressure points from the diaper. A thick, flakelike scale is present in both forms and is characteristic. Diaper wearing appears to play an important role in the genesis of infantile granular parakeratosis but the mechanisms are unclear. Therapeutic responsiveness to topical agents is ambiguous, however, spontaneous clearance after months to 1 year appears to be the rule.