Urticaria

Alternative names:

hives

Symptoms:

• itching (pruritus)
• swelling of the surface of the skin into red or skin colored welts (wheals) with clearly defined edges
  • sudden onset
  • rapid resolution
  • welts blanch to touch
  • new welts develop when the skin is scratched

• welts enlarge, spread or join together to form large flat raised areas
• welts change shape, disappear and reappear within minutes or hours

Signs and tests:

The diagnosis is primarily based on the appearance of the skin, and is confirmed by a history of exposure to an irritant or allergen. Occasionally, skin tests for allergy may be performed.