Hives and Angioedema Causes

Hives and angioedema are reactions of the skin to the release of histamine or other chemicals into the blood. This is often, although not always, due to an allergic reaction.

• There are many causes of hives and angioedema. At least half the time, the specific cause cannot be determined.



• Some of the more common triggers are the following:
  
  
  • Infections such as viral illnesses, especially in children
  
  
  
  • Allergies to food, medications, cosmetics, soaps, and detergents
  
  
  
  • Insect stings and bites
  
  
  
  • Transfusions of blood or blood products
  
  
  
  • Emotional and physical stress
  
  
  
  • Physical agents such as sunlight, heat, cold, water, or pressure


• Chronic hives is a case of hives that lasts longer than 6 weeks. This can happen to anyone, but it is most common in women aged 40-60 years. Chronic hives can last for months or even years, but this is unusual.



• Risk factors for hives and angioedema include the following:
  
  
  • A previous case of hives or angioedema
  
  
  
  • A previous allergic reaction
  
  
  
  • Family members who have hives or angioedema