erythema

n. reddening of the skin due to inflammation (Medicine)

Erythema is an large abnormal redness of the skin caused by capillary congestion. It is one of the cardinal signs of inflammation. It can be caused by infection, massage, electrical treatments, acne medication, allergies, exercise or solar radiation (sunburn), any of which can cause the capillaries to dilate, resulting in redness. Erythema is a common side effect of radiotherapy treatment due to patient exposure to ionizing radiation.
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Erythema /er·y·the·ma/ redness of the skin due to congestion of the capillaries.erythem´atouserythe´mic erythema annula´re a type of erythema [more]Erythema - Community and Resources

Noun
1. abnormal redness of the skin resulting from dilation of blood vessels (as in sunburn or inflammation)
(hypernym) erythroderma
(hyponym) erythema multiforme

(n.)
A disease of the skin, in which a diffused inflammation forms rose-colored patches of variable size.