Rare diseases · Sign or symptom
Purpura
Red or purple spots on the skin
HP:0000979
What it means
Purpura (from Latin: purpura, meaning purple) is the appearance of red or purple discolorations on the skin that do not blanch on applying pressure. They are caused by bleeding underneath the skin. This term refers to an abnormally increased susceptibility to developing purpura. Purpura are larger than petechiae.
Depending on their size, purpuric lesions are traditionally classified as petechiae (pinpoint hemorrhages less than 2 mm in greatest diameter), purpura (2 mm to 1 cm) or ecchymoses (more than 1 cm).
Rare diseases that can present with this45
Very common80–99%
8- Cryoglobulinemic vasculitis
- Cutaneous small vessel vasculitis
- Eosinophilic granulomatosis with polyangiitis
- Immune-mediated thrombotic thrombocytopenic purpura
- Immunoglobulin A vasculitis
- Severe hereditary thrombophilia due to congenital protein S deficiency
- Simple cryoglobulinemia
- Stormorken-Sjaastad-Langslet syndrome
Common30–79%
9- Acute promyelocytic leukemia
- Congenital syphilis
- Familial hemophagocytic lymphohistiocytosis
- Fetal and neonatal alloimmune thrombocytopenia
- Immune thrombocytopenia
- Kaposiform hemangioendothelioma
- Kasabach-Merritt phenomenon
- Severe hereditary thrombophilia due to congenital protein C deficiency
- Wiskott-Aldrich syndrome
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: Blood spots
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.