Rare diseases · Sign or symptom
Ochronosis
HP:0030764
What it means
Brown or blue-gray discoloration of the skin that can present on the axillary and inguinal areas, face, palms or soles. In addition, blue-black discoloration can be apparent on skin overlying cartilage in which the pigment is deposited, such as the ears. This is a characteristic manifestation of alkaptonuria, which is an autosomal recessively inherited deficiency of homogentisic acid oxidase that results in accumulation of homogentisic acid in collagenous structures. The sclerae are also typically involved.
Rare diseases that can present with this1
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Ochronotic arthritis
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.