ochronosis
Noun: 1. A pathological condition characterized by the bluish-black or brownish-black discoloration of connective tissues, especially cartilage, due to the accumulation of a homogentisic acid-derived pigment. This condition is most commonly a symptom of the inherited metabolic disorder alkaptonuria but can also result from prolonged exposure to certain phenolic compounds.
- Medical Diagnosis: The term is used almost exclusively in medical contexts to describe a specific physical finding, often confirmed via biopsy or during surgery.
- The patient's history of dark urine and the ochronosis observed in the ear cartilage were diagnostic for alkaptonuria.
- Pathology confirmed ochronosis of the intervertebral discs.
- Symptom Description: It is used to specify the visible tissue pigmentation that results from an underlying biochemical process.
- A key feature of the disease is ochronosis, which causes a distinctive darkening of the skin over cartilage and the sclera of the eyes.
- Exogenous Ochronosis: Refers to the same pigmentation disorder caused by external factors, such as the long-term topical application of skin-lightening creams containing hydroquinone or exposure to phenol.
- The dermatologist diagnosed the facial discoloration as exogenous ochronosis resulting from chronic hydroquinone use.
- Ochronotic (Adjective): Describing something related to or affected by ochronosis.
- The surgeon noted ochronotic changes in the aortic valve.
- Tissue pigmentation (general)
- Connective tissue discoloration (descriptive)
- Normochromia (normal tissue coloration)
The meaning of "ochronosis" is highly specific and technical. It does not have common, everyday meanings or idiomatic uses. Its primary definition is the pathological accumulation of dark pigment in connective tissue. While alkaptonuria is the prototypical cause, the term correctly applies to the pigmentation itself, regardless of whether the cause is endogenous (genetic) or exogenous (from external toxins).
- an accumulation of dark pigment in cartilage and other connective tissue; usually a symptom of alkaptonuria or phenol poisoning