• Hives (Urticaria) Glossary of Terms

Glossary of Terms
  • Erythema: Superficial reddening of the skin as a result of relaxation of the blood capillaries from injury or irritation.
  • Edema: Abnormal collection of fluid in the cavities or tissues of the body.
  • Dermis: The layer of skin below the epidermis containing blood capillaries, nerve endings, sweat glands, hair follicles and other structures.
  • Epidermis: The outermost layer of skin overlying the dermis.
  • Pruritus: Severe itching of the skin.
  • Angioedema: An abnormal swelling of the deeper layers of the skin usually caused by an allergic reaction.
  • Histamine: A specific chemical released by the cells in response to injury or in allergic or inflammatory reactions that causes contractions of smooth muscles and relaxation of the capillaries.