Erythema
symptom
Erythema (Ancient Greek: ἐρύθημα, from Greek erythros 'red') is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries. It occurs with any skin injury, infection, or inflammation. Examples of erythema not associated with pathology include nervous blushes.
Types
Causes
It can be caused by infection, massage, electrical treatment, acne medication, allergies, psoriasis, mast cell activation syndrome (MCAS), exercise, solar radiation (sunburn), photosensitization, acute radiation syndrome, mercury toxicity, blister agents, niacin administration, or waxing and tweezing of the hairs—any of which can cause the affected capillaries to dilate, resulting in redness. Erythema is a common side effect of radiotherapy treatment due to patient exposure to ionizing radiation.
Diagnosis
Erythema disappears on finger pressure (blanching), whereas purpura or bleeding in the skin and pigmentation do not. There is no temperature elevation, unless it is associated with the dilation of arteries in the deeper layer of the skin.
The public source identifies “Erythema” as symptom. This brief keeps that definition visible, then builds a research path around Erythema and symptom.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Erythema”, the useful work is to connect “symptom” to the records capable of establishing context and consequence.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 27, 2026. The linked authority identifier is Q1166142. The Library of Congress control number is sh85044740. 1 of 1 selected statements include explicit references; 1 carry qualifiers and 0 use preferred rank.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Erythema”, its source revision and the description used here.
- Expand the search: follow Erythema primary sources, Erythema archive and Erythema research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Erythema”?
- Which cited source is closest to the event, object or claim?
- Which institution is responsible for the underlying evidence?
Search terms from this dossier
This entry incorporates text from “Erythema” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.