Topical Hydroquinone use leading to Endogenous Ochronosis: A Case Report

Abstract

Ochronosis is a rare disease characterized by skin pigment changes and degenerative arthritis caused by deposition of homogentisic acid in joint cartilage. There are exogenous and endogenous forms of the disease with the endogenous form typically caused by alkaptonuria, or a defect in homogentisic acid oxidase enzyme. In this report we present a previously undocumented case of endogenous ochronosis caused by topical hydroquinone use in a 69-year-old Caucasian male without alkaptonuria.