Hives (urticaria) is an inflammatory skin condition that causes bumps, or wheals, to form on the skin. Urticaria can occur with symptoms like angioedema (swelling) and headaches.
Hives arise due to the activity of skin cells and the release of histamine. Your immune system releases this chemical in response to an allergen, which causes symptoms. These symptoms typically resolve on their own within one week. Some people develop chronic urticaria, in which flares recur regularly after six weeks of onset.2 Treatments for hives include managing symptoms and steering clear of any triggers.
About 20% of people experience hives at some point in their life.3 Hives can significantly impact your quality of life, but several successful therapies exist to reduce symptoms.
Types of Hives
Hives cases are primarily classified based on the cause and how long they persist. There are several classifications: acute, chronic spontaneous, and inducible urticaria. The classification influences the treatments for hives.
Acute Urticaria
Acute urticaria refers to cases that resolve on their own within six weeks of initial onset. About two-thirds of all hives cases are acute.4 The causes of this type are usually unknown (idiopathic). Symptoms can also arise due to allergic reactions or an underlying infection.5
Chronic Spontaneous Urticaria
Hives are chronic if symptoms persist longer than six weeks. Most of these cases are chronic spontaneous urticaria, in which the issue is idiopathic. Healthcare providers usually cannot identify a specific trigger or cause. About 1% of people in the United States have this type of hives.6
Inducible Urticaria
Inducible urticaria, or physical urticaria, arises due to an identified trigger or external factor. Common triggers include:7
- Allergens (e.g., pet dander)
- Cold
- Exercise
- Exposure to sunlight
- Heat
- Pressure on the skin
- Water or being wet
- Wearing or touching latex
Inducible urticaria can impact people of all ages. About 20% to 30% of chronic hives cases are inducible.
