ochronosis

Etiology

• pathological condition in certain patients with alkaptonuria
• hydroquinone

Pathology

• cartilage degeneration results osteoarthritis & chondrocalcinosis, particularly of the spine

Clinical manifestations

• pigmentation of cartilage
• pigmentation of other tissues may occur
  • muscle
  • epithelial cells
  • dense connective tissue
• pigmentation of:
  • sclera
  • mucous membrane of the lips
  • skin of the ears, face & hands

Laboratory

• standing urine is dark in color & contains pigmented* casts

* pigmentation occurs secondary to oxidation of homogentisic acid

More general terms

• arthritis

Additional terms

• alkaptonuria
• homogentisate