Granular Parakeratosis

Granular parakeratosis is a rare, benign, idiopathic condition that is best categorized as a reaction pattern rather than a distinct disease. The condition presents as red-to-brown scaly-to-hyperkeratotic papules or plaques typically in intertriginous areas. The condition has been reported in patients of all ages and is more commonly seen in women than in men. Granular parakeratosis was originally thought to be a contact dermatitis to personal hygiene products such as deodorants and antiperspirants; however, cases have been reported in the absence of personal hygiene products in the affected areas which discredited contact dermatitis as the etiology. Granular parakeratosis was first described in 1991 by Northcut et al. as "axillary granular parakeratosis." Case reports have also noted granular parakeratosis in other intertriginous areas as well as non-intertriginous body areas such as the face. Granular parakeratosis typically self-resolves in one-month to one-year, and responses to various treatments have been inconsistent among reported cases.