Exogenous ochronosis: a comprehensive review of the diagnosis, epidemiology, causes, and treatments.

Exogenous ochronosis (EO) can be an unintended psychologically troubling condition for patients who are already being treated for longer-term hyperpigmentation disorders such as melasma. Early diagnosis is key in order that the offending agent can be stopped to prevent further disfiguring discoloration. EO can be diagnosed in the right clinical setting with the aid of dermatoscopy, which can assist in early diagnosis and may negate the need for a biopsy. Laser modalities using Q-switched lasers of longer wavelengths and combination laser dermabrasion treatments have shown the most significant results with minimal adverse events. However, further large-scale studies are needed to determine optimal treatment modalities. Although considered uncommon, the incidence of EO will likely continue to increase with the growth of immigrant populations and the use of skin-lightening agents above the FDA's recommended over-the-counter concentrations, without the guidance of a dermatologist.