What is Erythema? Erythema refers to skin reddening that occurs with congestion of local dilated blood vessels.

What causes Erythema?

Erythema can be a normal, transient response to stimuli, such as pressure or massage, heat, sun exposure, caustic substances, and intense emotions. However, it is also a common symptom of several systemic and cutaneous conditions that stimulate the vascular and neural structures of the region affected. These conditions often involve dysregulation of the immune system or hormonal levels. 

Conditions that can present with Erythema:

  • Allergic reactions to food, medication, insect bites, or other external irritants.
  • Non-allergic reactions to drugs, such as flushing after niacin administration.
  • Viral or bacterial infections.
  • Primary inflammatory dermatologic conditions, such as rosacea, eczema, psoriasis, and acne.
  • Systemic conditions, including systemic lupus erythematosus, dermatomyositis, rheumatoid arthritis, liver disease, and thyroid disease.

Source: Abdlaty, R., & Fang, Q. (2021). Skin erythema assessment techniques. Clinics in Dermatology, 39(4), 591–604.