What Is Urticaria and What Causes It?

Definition

Urticaria (hives) are red, itchy welts that result from a skin reaction. The welts vary in size and appear and fade repeatedly as the reaction runs its course.

If the welts appear for more than six weeks and recur frequently over months or years, it is called chronic hives.

 

Causes

The cause of urticaria is not clear. The skin reaction may be triggered by:

  • Pain medications
  • Insects or parasites
  • Infection
  • Scratching
  • Heat or cold
  • Stress
  • Sunlight
  • Exercise
  • Alcohol or food
  • Pressure on the skin, as from a tight waistband
* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.