FAQ: Chronic Idiopathic Urticaria (CIU)

by Peter Jaret Health Writer

What is chronic idiopathic urticaria?

Chronic idiopathic urticaria (CIU) is a persistent form of hives that occurs without a known cause. Urticaria is the medical name for hives. Although the symptoms of hives -- itchy red bumps or welts -- often go away on their own, they can become chronic, lasting six weeks or more. Some cases of hives are caused by sun, heat, cold, pressure and other exposures. But in about 7 out of 10 cases, doctors can’t identify a cause. The term idiopathic means “no known cause.”

Recently, about half of cases of CIU have been linked to abnormal immune responses similar to an allergic reaction. But researchers have been unable to determine what triggers the abnormal immune response.

How long does chronic idiopathic urticaria last?

Episodes vary widely. In one recent survey, about 50 percent of hives sufferers reported outbreaks lasting between 6 and 12 weeks. Another 18 percent reported outbreaks of three to six months. About 10 percent reported an outbreak lasting 7 to 12 months. The remainder suffered the symptoms of chronic urticaria for years.

How is CIU diagnosed?

Doctors may recommend tests to rule out other skin conditions that look like hives. But there is no reliable test for CIU. CIU is diagnosed on the basis of the symptoms and how long they have lasted.

How many people have CIU?

About 0.5 percent – or one in 200 people – suffer from CIU during their lifetimes.

Can CIU be treated?

A variety of treatments can ease the symptoms of itching and redness. Physicians often start by prescribing drugs called H1 antihistamines. These medications block the reaction that causes the symptoms of hives. H1 antihistamines reduce symptoms in about 75 percent of people with CIU. Common examples include fexofenadine and desloratadine. Drugs that suppress allergic reactions, including corticosteroids and cyclosporine, may also help ease symptoms in some patients.

The newest medication for CIU is omalizumab. It targets an antibody produced by the immune system. Approved in 2014 in the U.S., omalizumab is recommended for patients with CIU who cannot be adequately treated with H1 antihistamines. The drug is given in one or more injections, once every four weeks. In one recent study, patients taking omalizumab experienced a 70 percent reduction in itching severity, compared to only 36 percent who took a placebo.

Do treatments for CIU have side effects?

Like almost all effective drugs, the medications used to control CIU have side effects. It’s always important to read the warnings on medication packages and to talk to your doctor about side effects.

Can home remedies ease the symptoms of CIU?

The most important thing you can do is avoid irritating affected areas. Wear loose, light clothing. Use mild soaps and towel your skin dry very gently. Take a shower or use a cool washcloth to cool your skin.


“Chronic urticaria: new management options,”Journal of the World Allergy Organization, 2014

“Omalizumab in the treatment of chronic urticaria,” Actas Dermosifiliograficis, 2014

“What is chronic idiopathic urticaria?”, Xolair.com

“Chronic idiopathic urticaria,”Medscape.com

“Chronic Hives,” Mayo.com

Peter Jaret
Meet Our Writer
Peter Jaret

Peter Jaret is the author of several health-related books, including "In Self-Defense: The Human Immune System" (Harcourt Brace), "Nurse: A World of Care" (Emory University Press), and "Impact: On the Frontlines of Public Health" (National Geographic). A frequent contributor to National Geographic, The New York Times, Reader’s Digest, Health, More, AARP Bulletin, and dozens of other periodicals, Jaret is the recipient of an American Medical Association award for journalism and two James Beard awards. He lives in Petaluma, Calif.