A late and difficult diagnosis of ochronosis.

Alkaptonuria is a rare autosomal recessive disorder of metabolism caused by deficiency of homogentisic acid oxidase and resulting in accumulation of homogentisic acid in collagenous structures. This causes the classic clinical triad: (1) homogentisic aciduria (urine blackens on standing when oxidized or alkalinized); (2) eumelanin-like pigmentation of skin, sclera, cartilages, etc and (3) degenerative ochronic arthropathies usually in the fourth decade of life. Other important but more rare consequences of alkaptonuric ochronosis are cardiovascular and urinary tract involvement. We present a case of ochronosis with multiple visceral involvement: skin (fingers, ear sclera), severe spondylarthropaty with extensive calcifications of intervertebral discs and reduced mobility, osteoarthritis of both knees, right hip ostonecrosis, cardiovascular involvement (severe stenosis and insufficiency of aortic valve that) and urinary tract involvement (nephrolitiasis)