Rare diseases · Sign or symptom
Allergy
HP:0012393
What it means
An allergy is an immune response or reaction to substances that are usually not harmful.
In everyday care
Most people with this sign do not have a rare disease — it appears in common conditions far more often. These general reference pages cover the same topic:
Rare diseases that can present with this16
Common30–79%
9- Acral peeling skin syndrome
- Idiopathic intracranial hypertension
- IgG4-related aortitis
- IgG4-related ophthalmic disease
- Immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome
- Indolent systemic mastocytosis
- Intellectual disability-autism-speech apraxia-craniofacial dysmorphism syndrome
- Selective IgM deficiency
- T-B-NK- severe combined immunodeficiency due to adenosine deaminase deficiency
Sometimes5–29%
4The 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, and Orphanet separately records 1 disease where this sign is specifically absent. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.
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.