Raised, itchy welts that last less than 24 hours in any one spot are typical.

HIVES/URTICARIA

Hives (aka urticaria) is a common, itchy, allergic condition of the skin. Below are the approximate percentages of important causes.

Cause of Hives

• Idiopathic: 50%
• Viral infection, e.g. cold: 40% (closer to 50-60% in chidren)
• New medication: 5%
• Food: 3%

All patients with new onset urticaria have by definition "acute urticaria". If the urticaria lasts longer than six weeks, it is called "chronic urticaria". About 20-30% of acute cases go on to chronic, but it is impossible to know at the outset which. Fifty percent of cases of chronic urticaria will be gone in one year. 80% will resolve in five years.

Other Key Points

• Urticaria is common. About 20% of people will experience at least one episode of hives in their lifetime.
• Urticaria affects women twice as often as men.
• Significant swelling of the skin and/or underlying tissue is called angioedema and can be serious. (Seek help immediately if you experience angioedema.)
• Rarely hives may be triggered by heat, cold, pressure etc. These are called the physical urticarias.

Red lines where scratched. This is called dermatographism.

Urticaria in a child. A viral infection is most likely the cause of hives in children.

Annular lesions may form

Urticaria in a teenage boy several days after starting minocycline for acne. Key points are 1) very itchy and 2) lesions move around within hours.

RegionalDerm

Who is Dr. White? | Privacy Policy | FAQs | Use of Images | Contact Dr. White