Where Does Ochronosis Occur?

Ochronosis is the bluish black discoloration of certain tissues, such as the ear cartilage and the ocular tissue, seen with alkaptonuria, a metabolic disorder.

Why does ochronosis happen?

Ochronosis occurs because of deposition of phenols (such as homogentisic acid and hydroquinone) as plaques in the matrix of cartilage. The pigments can also be incorporated into collagen and elastin fibers. In the skin, the pigment alters the structure of the fibers, causing enlargement and curling.

Who gets ochronosis?

Epidemiology and pathophysiology. The incidence of alkaptonuria has been reported to be as common as 1:250,000 to 1:1,000,000 people, more common in areas of high consanguinity. The condition affects men and women equally.