erythema

erythema, more or less diffuse redness of the skin due to concentration of an abnormally large amount of blood within the small vessels of the skin (hyperemia), as in burns. Erythema nodosum is often associated with systemic diseases such as tuberculosis and rheumatic fever. Tender, bright red, slightly elevated nodules develop along the shins. Erythema multiforme can have a number of causes, including viral and bacterial infection, chronic disease of the visceral organs, or allergic reactions to drugs.

Abnormal skin redness from increased blood flow, caused by dilation and irritation of surface capillaries. It has a variety of manifestations. In erythema multiforme, a symptom complex seen in several diseases, spots appear suddenly, often with a bull's-eye pattern. It may become life-threatening in severe cases; in mild cases symptoms may recur. Hormone treatment may be effective. In erythema nodosum, a hypersensitivity reaction usually associated with strep infection (see streptococcus), drugs, or the disease sarcoidosis, painful red nodules appear in the deeper skin layer of the lower legs. They usually disappear over several weeks and do not recur. Another form of erythema is pellagra.

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Erythema is redness of the skin caused by capillary congestion.

Causes

It can be caused by infection, massage, electrical treatments, acne medication, allergies, exercise, solar radiation (sunburn), or waxing and plucking of the hairs -- 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.

In about 30-50% of cases, the cause of Erythema is unknown.

Associated conditions

• Erythema ab igne
• Erythema induratum
• Erythema infectiosum (or fifth disease)
• Erythema marginatum
• Erythema migrans
• Erythema multiforme (EM)
• Erythema nodosum
• Erythema toxicum
• Palmar erythema

See also

• Flushing (physiology)
• Rash
• Radiotherapy

References

External links

• UM