Chronic Hives and Swelling
Reviewed by: HU Medical Review Board | Last updated: February 2023
People with chronic hives have hives for at least 6 weeks. Chronic hives is also known as chronic urticaria. About half of people with chronic hives also have painful swelling called angioedema. Angioedema (an-jee-ow-uh-dee-muh) means swelling beneath the skin. It often affects:1-3
Most people with chronic hives cannot identify what causes their swelling.1-3
Angioedema is not usually life-threatening. But when swelling affects the throat or tongue, it can block the airways. This is a serious condition called anaphylaxis. It is usually linked to an allergic reaction.1-3
What are some signs of angioedema?
Angioedema may be the only symptom of chronic hives, or may occur with acute (short-term) hives. It is different from other types of swelling (edema) because it:1-3
- Appears within minutes to hours and disappears over a few hours to days
- Affects each side of the body differently
- Involves the face, lips, hands, feet, and genitals
- Often happens with other signs of an allergic reaction
- Is numb or tingling, not itchy
What causes angioedema?
There are 2 types of angioedema:1
- Histaminergic angioedema
- Bradykinin-mediated angioedema
Histaminergic angioedema happens when immune cells release a chemical called histamine. This type also creates hives and itchiness. Some causes include:4
- Chronic hives
- Allergic reactions
- Drugs that cause immune cells to release histamine
- Nonsteroidal anti-inflammatory drugs (NSAIDs) like Tylenol and ibuprofen
Bradykinin-mediated angioedema happens because of high levels of a chemical called bradykinin. This makes blood vessels larger and leads to swelling. This type does not come with hives or itchiness. Some causes include:4
- Drugs that increase bradykinin levels, such as ACE inhibitors for high blood pressure
- Genetic causes that lead to hereditary angioedema
People can also develop idopathic angioedema, which is swelling without a known cause. It happens without hives and is not caused by allergies, drugs, or other known triggers.4
How do doctors diagnose angioedema?
Doctors use your health history and physical exams to diagnose angioedema. If you have hives, they will first see if you are having an allergic reaction. They will ask about any recent exposures, activities, food, or medicines.1
They will also perform skin and blood tests for allergies. If doctors cannot identify a cause and symptoms last longer than 6 weeks, your doctor will consider a diagnosis of chronic hives.1
If you do not have hives, your doctor will ask about your family health history. They will also ask about any prescription drugs and supplements you take. They may order blood tests for hereditary angioedema. If they cannot identify a cause, doctors will consider a diagnosis of idiopathic angioedema.1,5
How is angioedema treated?
The priority is to make sure swelling does not affect your breathing. Your doctor will see if you have signs of airway blockage. If you do, they will give you epinephrine and information about treating anaphylaxis at home. They may also give you intravenous fluids and supplemental oxygen.3
Doctors will then treat you based on the type of swelling. For example, people with chronic hives are treated with antihistamines and steroids.1