Ochronosis

Ochronosis is the pigmentary complication of alkaptonuria, an autosomal-recessive deficiency of homogentisate oxidase causing homogentisic-acid accumulation. Deposition of dark pigment in cartilage (ears, nose, joints), sclera, and intervertebral discs causes dark urine on standing, bluish-black scleral/ear pigmentation, and a disabling spondyloarthropathy. Treatment is supportive (joint replacement, pain control); high-dose vitamin C and nitisinone have been tried.

Common Symptoms

Dark urine on standing; blue-black scleral/ear cartilage pigmentation; spondyloarthropathy/joint pain; ochronotic arthropathy

Causes and Pathogenesis

Homogentisate-oxidase deficiency causes homogentisic-acid accumulation and polymerization, depositing melanin-like pigment in connective tissues.

Treatment

Supportive; pain control; joint replacement; low-protein diet; nitisinone/vitamin C trial

Preventive Measures

Genetic counseling; early recognition; manage arthropathy.

Department to Visit

It is recommended to visit the Rheumatology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.