Erythema

Erythema is a skin condition characterized by redness or rash. There are many types of erythema, including photosensitivity, erythema multiforme, and erythema nodusum. Photosensitivity is caused by a reaction to sunlight and tends to occur when something, such as an infection or a medication, increases your sensitivity to ultraviolet radiation. Erythema multiforme is characterized by raised spots or other lesions on the skin. It is usually caused by a reaction to medications, infections, or illness. Erythema nodosum is a form of erythema that is accompanied by tender lumps, usually on the legs below the knees, and may be caused by certain medications or diseases.