Alkaptonuria with extensive ochronosis.

A 59-year-old woman with previously documented alkaptonuria was examined for extensive ochronosis of recent onset. The cause of the extensive skin pigmentations were thought to be secondary to decreased renal clearance of homogentisic acid because of a decline in the patient's renal function. If extensive or rapidly progressive skin pigmentation is noted in a patient with alkaptonuria, then evaluation of the patient's renal status should be done because unrelated renal disease has been reported in patients with severe ochronosis.