What Are Hives?

Hives, also known as urticaria, are an itchy skin rash that usually results from an allergic reaction to something you have eaten or touched.

Sometimes referred to as welts, hives cause red bumps or splotches on your skin which can itch, burn or sting. Hives can be very small or quite large, and sometimes they join together to cover large areas.

Urticaria allergy: What you need to know

Urticaria is an allergic reaction, which happens when your immune system encounters an allergen – a protein which is harmless to some, but causes an allergic reaction in others.

There are two main types of hives: acute urticaria, which doesn’t last long, and chronic urticaria, which happens several times a week and last for more than six weeks.

What are the symptoms of hives?

Hives can appear anywhere on the body and can look different on different people. Signs of acute hives usually include:

• Raised red bumps or welts
• Itchy skin
• The centers of the hives becomes pale when pressure is applied
• Swelling and puffiness under the skin.

Chronic hives look like acute hives but have slightly different characteristics. They can:

• Change size and shape
• Disappear and reappear
• Be brought on by exercise, stress and heat.

What causes hives?

Acute hives are usually an allergic reaction to something you have eaten or drunk, something you have touched, or medication you have taken. Hives can also be caused by stress or an infection.

The allergic reaction causes the immune cells within your skin to release chemicals, including histamine, which causes the hives to appear.

Chronic hives aren’t typically caused by an allergic reaction. They are often the result of a medical condition or infection.

How are hives treated?

Usually, hives will go away on their own. Your doctor may recommend allergy medications to relieve the symptoms and reduce the chances of them happening again.

At home treatments for relieving hives include taking a cool bath, applying a cold compress and wearing loose clothing.

Antihistamines can alleviate the symptoms of hives and reduce the severity of an allergic reaction. For chronic hives, which are harder to treat, allergy injections may be recommended to prevent allergic reactions.

Can I prevent hives?

Knowing what triggers your hives can help you to avoid the allergens that cause hives. Your doctor can perform an allergy test to help you to identify triggers if you aren’t sure.

When should I seek help with hives?

If your hives aren’t improving by themselves, or you notice any of the following, talk to your doctor:

• They last for more than a week
• They keep coming back
• They look infected
• They are causing severe itching.

If you experience any signs of anaphylaxis, which includes shortness of breath, wheezing, swelling of the face, mouth or lips, a tight throat, difficulty swallowing, dizziness, fainting or vomiting, seek emergency medical help.