ochronosis

A rare, autosomal recessive disease characterized by alkapton uria with pigmentation of the cartilages and sometimes tissues such as muscle, epithelial cells, and dense connective tissue; may affect also the sclera, mucous membrane of the lips, and skin of the ears, face, and hands, and cause standing urine to be dark-colored and contain pigmented casts; pigmentation is thought to result from oxidized homogentisic acid, and cartilage degeneration results in osteoarthritis, particularly of the spine. [G. ochros, pale yellow, + nosos, disease]
- exogenous o. pigmentation of the skin of the face and elsewhere from prolonged topical exposure to hydroquinone-containing bleaching creams.

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ochro·no·sis .ō-krə-'nō-səs n, pl -no·ses -.sēz a condition often associated with alkaptonuria and marked by pigment deposits in cartilages, ligaments, and tendons
ochro·not·ic -'nät-ik adj

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n.
the presence of brown-black pigment in the skin, cartilage, and other tissues due to the abnormal accumulation of homogentisic acid that occurs in the metabolic disease alcaptonuria.

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ochro·no·sis (o″krə-noґsis) [Gr. ōchros pale + nos- + -sis] generalized deposition of dark pigment in the connective tissues, usually secondary to alkaptonuria (q.v.). It is characterized by urine that darkens on standing and visible dusky discoloration of the sclerae and ears. The pigment is a sequela of accumulation of homogentisic acid in the connective tissues. ochronotic adj

Dark pigmentation of ear cartilage in ochronosis.


Medical dictionary. 2011.

Look at other dictionaries:

  • Ochronosis — Classification and external resources Homogentisic acid ICD 10 E …   Wikipedia

  • ochronosis — Deposition of dark brown pigment in cartilage, joint capsules and other tissues, usually as a result of alkaptonuria …   Dictionary of molecular biology

  • ochronosis — noun An autosomal recessive metabolic disorder that causes an excess of homogentisic acid, resulting in adverse pigmentation, calcification, and inflammation of cartilaginous and related tissue throughout the body …   Wiktionary

  • ochronosis — n. (Medicine) yellowing of the skin and whites of the eyes that is caused by the presence of melanin deposits in the connective or cartilage tissues as the result of a build up of homogentisic acid (characteristic of the disease alkaptonuria) …   English contemporary dictionary

  • ochronosis — ochro·no·sis …   English syllables

  • ochronosis — n. the presence of brown black pigment in the skin, cartilage, and other tissues due to the abnormal accumulation of homogentisic acid that occurs in the metabolic disease alcaptonuria …   The new mediacal dictionary

  • ochronosis — noun an accumulation of dark pigment in cartilage and other connective tissue; usually a symptom of alkaptonuria or phenol poisoning • Hypernyms: ↑symptom …   Useful english dictionary

  • exogenous ochronosis — ochronosis induced by exposure to chemicals such as phenolic compounds or hydroquinone …   Medical dictionary

  • pseudo-ochronosis — pseu·do ochro·no·sis (soo″do o kroґno sis) a condition resembling ochronosis, but not caused by a disorder of metabolism …   Medical dictionary

  • Охроноз (Ochronosis) — появление темно коричневых пигментных пятен на коже, хрящах и других тканях вследствие аномального скопления в них гомогентизиновой кислоты (наблюдается при заболевании, связанном с нарушением обмена веществ алкаптонурии). Источник: Медицинский… …   Медицинские термины

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