ochronosis /ō′krənō″sis/ [Gk, ochros, yellow, osis] , an inherited error of protein metabolism characterized by an accumulation of homogentisic acid, resulting in degenerative arthritis and brown-black pigment deposited in connective tissue and cartilage. It is often caused by alkaptonuria or poisoning with phenol. Bluish macules may be noted on the sclera, fingers, ears, nose, genitalia, buccal mucosa, and axillae. Urine color may be dark. See also alkaptonuria.
