Exogenous ochronosis: a review for clinicians

Abstract

Exogenous ochronosis has been described as a complication associated with the use of hydroquinone for skin lightening in dark-skinned individuals, but is now also increasingly recognized as a possible complication of hydroquinone use for treatment of pigmentary disorders such as melasma in fairer-skinned individuals. Diagnosis of this condition is difficult in early cases. Dermoscopy and reflectance confocal microscopy have been put forward as possible diagnostic aids. It is important that clinicians are aware of this complication of hydroquinone therapy. In this article, we briefly discuss the clinical findings, pitfalls in diagnosis, etiopathogenesis and possible treatment options of this difficult-to-treat condition.