Granular parakeratosis: four paediatric cases.

Axillary granular parakeratosis (GP) was first described in 1991 as a peculiar eruption presenting with erythematous hyperpigmented and hyperkeratotic papules and plaques of the cutaneous folds frequently associated with pruritus. Histopathology shows a characteristic picture with a conspicuous granular appearance of the parakeratotic horny layer. Until now, only 24 adults, mainly women aged over 40 years, have been reported with GP. We demonstrate that this condition can also occur in young children. Four children aged between 10 and 24 months had asymptomatic hyperpigmented scaling papules 2-3 mm in diameter located on the groin, lower back, buttocks and flanks. In all cases the mothers reported the habit of frequent washing followed by application of many topical products. Biopsy revealed the same features in all four patients: the epidermis showed a thickened horny layer with a unique compact parakeratosis with maintenance of the stratum granulosum and marked retention of keratohyaline granules throughout the stratum corneum.