Rare diseases · Sign or symptom
Oral ulcer
Mouth ulcer
HP:0000155
What it means
Erosion of the mucous mebrane of the mouth with local excavation of the surface, resulting from the sloughing of inflammatory necrotic tissue.
Rare diseases that can present with this26
Common30–79%
8Sometimes5–29%
13- Fixed drug eruption
- Florid cemento-osseous dysplasia
- Glycogen storage disease due to glucose-6-phosphatase deficiency type Ib
- Idiopathic non-lupus full-house nephropathy
- Langerhans cell histiocytosis
- Methotrexate toxicity
- Mixed connective tissue disease
- Pediatric systemic lupus erythematosus
and 5 more in this range
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: Mouth sore · Oral mucosal ulceration
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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.