Ochronosis E70.23

Virchow

Ochronosis (from Ochros, Greek for yellow) refers to a dyschromia of the skin and other tissues which is either due to a congenital metabolic defect (endogenous ochronosis/endogenous dyschromia, see below alkaptonuria) or is caused exogenously (exogenous ochronosis) by the use of bleaching agents containing hydroquinone(exogenous dyschromia).

• Endogenous ochronosis (see below alkaptonuria)
• Exogenously acquired ochronosis (cosmetic ochronosis caused by bleach).

In ochronosis, the entire skin can be discolored. However, there are certain predilection sites such as the ears, nose, sclerae, palms and soles of the feet. Discoloration of the nails can only be observed in alkaptonuria. In areas where the skin is in contact with the cartilage (ears, nose - especially the tip of the nose) and on the sclerae, the areas turn gray or gray-bluish.

• Endogenous Ochronosis: No causal therapy possible, see below Alkaptonuria.
• Exogenous chronosis: Therapy is not necessary. Avoid the triggers.

1. Findlay GH et al. (1975) Exogenous ochronosis and pigment colloid milium from hydroquinone bleaching creams. Br J Dermatol 93: 613-622
2. Hortobagyi J et al (1992) A rare metabolic disease: alkaptonuria-ochronosis. Dermatologist 43: 580-582

3. Lazar M et al. (2023) Exogenous Ochronosis: Characterizing a Rare Disorder in Skin of Color. J Clin Med 12:4341.

4. Teller H et al. (1973) On the clinic and histopathology of endogenous ochronosis. Dermatologist 24: 537-543