Erythema vs. Rash — What's the Difference?

Erythema (from the Greek erythros, meaning 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.

A rash is a change of the human skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin.

Redness of the skin caused by dilatation and congestion of the capillaries, often a sign of inflammation or infection.

Resulting from or acting with ill-considered haste or boldness.

Abnormal redness and inflammation of the skin, due to vasodilation.

A visible lesion or group of lesions on the skin, caused by any of numerous factors including infectious agents, drugs, and allergies.

Skin redness from sunburn or chemical irritation

An outbreak of many instances within a brief period

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

Acting too quickly without considering the consequences and risks; not careful; hasty.

Abnormal redness of the skin resulting from dilation of blood vessels (as in sunburn or inflammation)

Of corn or other grains: so dry as to fall out of the ear with handling.

Requiring swift action; pressing; urgent.

Taking effect quickly and strongly; fast-acting.

(archaic) rashly

An area of inflamed and irritated skin characterized by reddened spots that may be filled with fluid or pus; also, preceded by a descriptive word , an illness characterized by a type of rash.

(figuratively)

An irregular distribution or sprinkling of objects resembling a rash (sense 1).

An outbreak or surge in problems; a spate, string, or trend.

(historical) Chiefly preceded by a descriptive word: a fabric with a smooth texture woven from silk, worsted, or a mixture of the two, intended as an inferior substitute for silk.

(obsolete) A soft crackling or rustling sound.

(transitive)

To forcefully move or push (someone or something) in a certain direction.

To break (something) forcefully; to smash.

To emit or issue (something) hastily.

(rare) Usually followed by up: to prepare (something) with haste; to cobble together, to improvise.

(intransitive)

To move forcefully, hastily, or suddenly; to dash, to rush.

Of rain: to fall heavily.

Chiefly followed by against, at, or upon: to collide or hit.

Chiefly followed by away, down, off, out, etc.: to pluck, pull, or rip (something) violently.

To hack, slash, or slice (something).

(rare) Chiefly followed by out: to scrape or scratch (something); to obliterate.

To pull off or pluck violently.

To slash; to hack; to cut; to slice.

To prepare with haste.

A fine eruption or efflorescence on the body, with little or no elevation.

An inferior kind of silk, or mixture of silk and worsted.

Sudden in action; quick; hasty.

Requiring sudden action; pressing; urgent.

Esp., overhasty in counsel or action; precipitate; resolving or entering on a project or measure without due deliberation and caution; opposed to prudent; said of persons; as, a rash statesman or commander.

Uttered or undertaken with too much haste or too little reflection; as, rash words; rash measures.

So dry as to fall out of the ear with handling, as corn.

Any red eruption of the skin

A series of unexpected and unpleasant occurrences;

Imprudently incurring risk;

Marked by unthinking boldness; with defiant disregard for danger or consequences;