The endogenous variety is an autosomal-recessive disease, known as alkaptonuria, that is caused by a lack of homogentisate oxidase enzyme.

[2] Exogenous ochronosis is an avoidable dermatitis that can be caused by the topical application of compounds such as hydroquinone or phenols.

[3] Hydroquinone-induced exogenous ochronosis was found in 1975 by Findlay, who observed the condition in patients who used skin lightening creams containing the compound.

[8] This may be due to aesthetic or social-standing reasons, in areas where a lighter skin tone is considered to be a sign of wealth or beauty.

Due to concerns about its side effects, it was almost banned by the FDA in 2006, as medical issues of carcinogenicity and reports of disfiguring ochronosis existed.

[12] Ochronosis occurs because of deposition of phenols (such as homogentisic acid and hydroquinone) as plaques in the matrix of cartilage.

The pigment can also be excreted by glandular cells in apocrine and ceruminous sweat glands, as well as breast and prostate tissue.

[2] Awareness of this is important, as dermatologists may think the symptoms a patient is exhibiting are a melasma, and prescribe a hydroquinone-containing cream.