Symptoms & Signs
Urine in an infant’s diaper may darken and can turn almost black after several hours. However, many persons with this condition may not know they have it until mid-adulthood (around age 40), when joint and other problems occur.
Symptoms may include:
* Arthritis (especially of the spine) that gets worse over time
* Darkening of the ear
* Dark spots on the white of the eye (sclera) and cornea
Diagnosis & Tests
A urine test (urinalysis) is done to test for alkaptonuria. If ferric chloride is added to the urine, it will turn the urine a black color in patients with this condition.
Reviewed By : Chad Haldeman-Englert, MD, Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc