Chronic Idiopathic Urticaria


What is urticaria?

Urticaria (pronounced ur·tuh·keh·ree·uh) is another word for hives. It’s estimated that 20 percent of people in the United States will develop hives – an itchy skin rash accompanied by raised, red welts or spots – at some point in their lives. The development of hives is often related to an allergic reaction, usually to food, latex or insect venom.

What is chronic idiopathic urticaria (CIU)?

Some people develop hives in which symptoms come and go for six or more weeks. These are known as chronic hives or chronic urticaria.

Sometimes you and your doctor are unable to identify what’s causing your hives to keep coming back. Often the hives can occur on different parts of the body. When this happens, the hives are called chronic idiopathic urticaria (CIU). Idiopathic means “of unknown cause.”

Another name for CIU is chronic spontaneous urticaria (CSU).

CIU outbreaks can appear at any time without triggers. Chronic urticaria is not contagious. The symptoms of CIU are not life-threatening, but, CIU can cause extreme discomfort and greatly impact quality of life.

How common is CIU?

CIU affects approximately 1.6 million people in the United States. CIU most often occurs in people between the ages of 20 and 40. Women are twice as likely to have CIU than men.


What causes CIU?

CIU is thought to be an immune system response. For this reason, it is best to see a board certified allergist trained in immunology.

Photo showing what hives look like

How is chronic idiopathic urticaria diagnosed?

When you and your doctor are unable to identify what’s causing your chronic hives, it’s likely chronic idiopathic urticaria.

On your first visit to the doctor, you may be asked the following questions to try to pinpoint what’s causing the hives:

  • When and where on the body do hives occur?
  • Is there any swelling?
  • How long do symptoms last?
  • What were you doing at the time hives occurred?
  • What medications (if any) are you taking?
  • Are there any other symptoms?

A blood test can help with diagnosis since blood cells in CIU patients often manufacture enormous amounts of histamine.

Your doctor will also ask what foods you were eating at the time of symptoms to determine if a food allergen caused your hives.

How is chronic idiopathic urticaria treated?

CIU is not a life-long condition; it usually goes away by itself over a period of days, weeks or months. Meantime, doctors and patients work together to find the most appropriate treatment and symptom management strategy.

CIU guidelines recommend a step-based approach to treatment, starting with over-the-counter antihistamines, preferably non-sedating ones. (Since CIU is a whole body condition, topical skin creams are not considered a treatment.)

If that doesn’t help, then H2 blockers are the next step. These block production of the histamine that causes hives. Doctors might also consider montelukast, which blocks leukotrienes, a chemical involved in inflammation.

Another consideration is omalizumab, an anti-IgE biologic given by injection (usually once a month) to block IgE antibodies involved in the production of histamine.

Other Chronic Idiopathic Urticaria Articles

Ask the Allergist: Pinpointing the Cause of Hives

Ask the Allergist: A Look at Chronic Idiopathic Urticaria

Webinar: When Histamine Meets the Skin: The Trials and Tribulations of Chronic Idiopathic Urticaria

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