Smith, now 46, was born with alkaptonuria, a rare genetic disorder that led to severe arthritis in his early 40s.    From Wordnik.com.  [Edmonton Sun] Reference

Large blisters, like these, are called bullae alkaptonuria, ochronosis X-ray lower lumbo-sacral spine and sacro-iliac joints showing normal sacro-iliac joints and calcification of intervertebral discs alkaptonuria, ochronosis grossly calcified intervertebal discs alkaptonuria, ochronosis early ankylosis of spine alkaptonuria, ochronosis bluish spots on his sclera alkaptonuria, ochronosis Bluish discoloration os ear cartillage hypertrophic osteoarthropathy Note diffuse periosteal new bone formation of the distal radius and ulna.    From Wordnik.com.  [Recently Uploaded Slideshows] Reference