Erythema

Erythema
Characteristic "bull's eye" rash (erythema migrans) of early Lyme disease
Pronunciation
SpecialtyDermatology

Erythema (/ˌɛrɪˈθiːmə/ ⓘ; 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.[citation needed]

See also

References

  1. ↑ Mosby's Medical Dictionary (9th ed.). St. Louis, Missouri: Elsevier. 2013. ISBN 978-0-323-08541-0.
  2. ↑ "Erythema". Mosby's Medical, Nursing & Allied Health Dictionary (Fourth ed.). Mosby-Year Book. 1994. p. 570.
  3. ↑ Valent P, Hartmann K, Bonadonna P, Niedoszytko M, Triggiani M, Arock M, Brockow K (2022-05-23). "Mast Cell Activation Syndromes: Collegium Internationale Allergologicum Update 2022". Int Arch Allergy Immunol. 183 (7): 693–705. doi:10.1159/000524532. PMC 9393812. PMID 35605594.
  4. ↑ Jane C. Quinn; Yuchi Chen; Belinda Hackney; Muhammad Shoaib Tufail; Leslie A. Weston; Panayiotis Loukopoulos (2018), "Acute-Onset High-Morbidity Primary Photosensitisation in Sheep Associated with Consumption of the Casbah and Mauro Cultivars of the Pasture Legume Biserrula", BMC Veterinary Research, 14 (1): 11, doi:10.1186/s12917-017-1318-7, PMC 5765607, PMID 29325550
  5. ↑ Vesicant Archived 2017-12-12 at the Wayback Machine EFFECTS
  6. ↑ Weterle R, Rybakowski J (Mar–Apr 1990). "Test niacynowy w schizofrenii" [The Niacin Test in Schizophrenia]. Psychiatr Pol (in Polish). 24 (2): 116–20. PMID 2084715.
  7. ↑ McKay, Marilynne (1990), "Office Techniques for Dermatologic Diagnosis", in Walker, H. Kenneth; Hall, W. Dallas; Hurst, J. Willis (eds.), Clinical Methods: The History, Physical, and Laboratory Examinations (3rd ed.), Boston: Butterworths, ISBN 978-0-409-90077-4, PMID 21250056, retrieved 2026-07-26
  8. ↑ Marks, JAMES G.; Miller, JEFFREY J. (2006-01-01), "CHAPTER 17 - Purpura", Lookingbill & Marks' Principles of Dermatology (Fourth Edition), Edinburgh: W.B. Saunders, pp. 235–244, doi:10.1016/B978-1-4160-3185-7.50022-9, ISBN 978-1-4160-3185-7, retrieved 2026-07-26