Urticaria or hives is a very common skin condition that affects 10-20% of the population at some point in their lifetime.
Urticaria is characterized by itchy, pink-red bumps on the skin (wheals) that usually last a few hours before fading without a trace. New areas may develop as old areas fade, and sometimes the bumps can join together forming larger swellings. While most cases of urticaria are self-limiting and of a short duration (acute urticaria), occasionally urticaria can become chronic or problematic.
Sometimes wheals may occur around the eyes or lips and cause swelling known as angioedema. If ever the swelling causes difficulty in breathing or swallowing, you should immediately go to an emergency room.
Types of urticaria:
- Acute urticaria is commonly caused by foods, drugs, infections and insect bites. Common foods that cause urticaria include nuts, chocolate, fish, eggs, tomatoes, berries, milk, food additives and preservatives.
- Sometimes urticaria is caused by physical factors such as sunlight, heat, cold, exercise, pressure and even vibrations (physical urticaria). Some people may get hives that form after stroking or scratching the skin, known as " dermatographism ", but are otherwise healthy.
- Urticaria lasting more than six weeks is termed chronic urticaria. Your dermatologist may need to ask you many questions to make a diagnosis and help find the cause, though sometimes the exact cause may not be identified. There are no specific tests for urticaria, but certain tests may be suggested depending on your history and examination findings.
How to treat urticaria:
Where the cause of urticaria can be identified, avoidance of the trigger is the most effective form of management. Antihistamines may be prescribed by your doctor to provide relief, and often work best if taken on a regular schedule to prevent hives from forming. No one antihistamine works best for everyone, so more than one antihistamine or different combinations may have to be tried and tested to find the one that works best for you.
In certain urticaria refractory to combinations of antihistamines, a short course of oral corticosteroid medications may have to be used to control the swelling.