Erythema is redness of the skin caused by capillary congestion.

It can be caused by infection, massage, electrical treatments, acne medication, allergies, exercise or solar radiation (sunburn), and 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.

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

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

See also

• Flushing (physiology)
• Rash
• Radiotherapy

hair loss: Alopecia areata (Alopecia totalis, Alopecia universalis, Ophiasis) - Androgenic alopecia - Telogen effluvium - Traction alopecia - Lichen planopilaris - Trichorrhexis nodosa

other follicular disorders: Hypertrichosis (Hirsutism) - Acne vulgaris - Rosacea (Perioral dermatitis, Rhinophyma) - follicular cysts (Epidermoid cyst, Sebaceous cyst, Steatocystoma multiplex) - Pseudofolliculitis barbae - Hidradenitis suppurativa

sweat disorders: eccrine (Miliaria, Anhidrosis) - apocrine (Body odor, Chromhidrosis, Fox-Fordyce disease)