Erythema

Definition

Erythema is redness of the skin caused by dilation of superficial capillaries. It can be a normal response to warmth or exercise, or a sign of inflammation, infection, allergic reaction, or medication effect.

Types

• Erythema migrans: Bullseye rash of Lyme disease.
• Erythema multiforme: Target-like lesions, often drug- or infection-related.
• Erythema nodosum: Painful red nodules on shins; sarcoidosis, IBD, TB, strep.
• Erythema infectiosum (fifth disease): 'Slapped cheek' in children, parvovirus B19.

Clinical Significance

Evaluate distribution, pattern, associated symptoms (fever, itching, pain). Mark borders to monitor spread in cellulitis. Assess for systemic signs suggesting serious reaction (Stevens-Johnson syndrome, anaphylaxis).

Nursing Interventions

Apply cool compresses, elevate affected area, administer antihistamines or corticosteroids as prescribed, and treat the underlying cause. Teach patients to report spreading redness, fever, or blistering.

NCLEX Relevance

Recognize erythema migrans (Lyme) and red 'slapped cheek' (fifth disease) patterns.