A rare, benign, acquired disorder of keratinization due to a defect in filaggrin processing, which results in the retention of keratohyalin granules in the epidermis. GP typically presents as reddish-brown, violaceous, or hyperpigmented scaly papules and plaques in intertriginous regions. Lesions can be asymptomatic or pruritic and friable. It is most commonly caused by heat, moisture, and friction. GP has a relatively chronic course and can persist for several months or can resolve spontaneously, but recurrence is common.