Diagnosis of alkaptonuria in children.

Thirty-nine patiens with alkaptonuria diagnosed in childhood were studied with repeated detailed clinical and biochemical examinations. Darkening of the urine, although varying from time to time, was present in all. Pigmentary changes in axillary regions began to appear at 8--10 years with concomitant staining of underwear. Ear cartilage staining occurred in only 1, and none had scleral involvement or anthropathy. Dark brown to black staining of ear cerumen is present even in earliest childhood. This distinctive symptom in a child with no other ochronotic manifestations and even normal urine colour should alert one to possible alkaptonnuria. Other findings are described in detail.