Ochronosis, often called alkaptonuric ochronosis,1 is an autosomal recessivemetabolic disorder that causes an excess of homogentisic acid, resulting in adverse pigmentation, calcification, and inflammation of cartilagenous and related tissue throughout the body.
Pigmented cartilage may appear blue due to scattering phenomenon, and to a lesser degree this may be true for skin with dermal deposition of this pigment. The skin of the axilla is very likely to be pigmented due to deposits of homogentisic acid in sudoriferous glands in these areas.1 The clinical features of this metabolic disorder are dark urine, pigmentation of the skin and arthritis. Particularly helpful is the almost constant presence of a patch of pigmentation (gray to brown in color) in the sclera, between the margin of the cornea and the outer or inner canthus. Because of the bluish color produced by the deep pigmentation, this condition may be confused with argyria.
^ ab Collins E, Hand R (2005). "Alkaptonuric ochronosis: a case report". AANA J73 (1): 41–46. PMID 15727283.
^ Bal S, Turan Y, Kocyigit H, Gurgan A, Kurtulumug S, Guvenc A (2007). "Ochronosis with cardiovascular involvement: a case report". Rheumatol Int.tbd (tbd): 479. doi:10.1007/s00296-007-0456-9. PMID 17899092.
