Urticaria is another name for hives. Idiopathic means that the cause of the hives is not known, unlike hives caused by a known allergic reaction, for example. Chronic means that this condition is more long-term, with hives that do not go away after six weeks or longer. This condition may also be called chronic spontaneous urticaria, or CSU, with spontaneous meaning that the cause is not known.

This article provides an overview of CIU, including the causes, symptoms, treatments, and how long it takes for it to go away.

Chronic Idiopathic Urticaria Causes

Even though the cause of the long-term ideopathic hives is, by definition, not known, there are possibilities that can be considered. It is important to consider possible causes because it helps to guide treatment and resolve the issue. For example, one possible cause of hives is allergies.

Possible causes or triggers of CIU include:

Infections: Viral or bacterial Blood transfusions Contact with certain materials: Latex is a common example Foods: Some types are more likely to cause an allergic reaction, such as shellfish and nuts Medications: Antibiotics are more common causes than others Environment: Extreme temperatures (hot or cold), sun, and pressure Autoimmune disease: 45% of people with CIU have an autoimmune disease, though it may not be the cause Bug bites or stings Plants and pollen Animals and their dander

Chronic Idiopathic Urticaria Symptoms

Since CIU is a version of hives, the symptoms are similar to acute hives (short-term). The biggest difference is that the symptoms last longer. These symptoms, such as red, itchy bumps on the skin, may go away and come back. They must be present for at least six weeks, and at least twice per week, to be considered chronic.

Outbreaks: What to Expect

CIU outbreaks are different for everyone. Red, itchy bumps, along with other symptoms, can appear with no warning or known cause. The symptoms can last weeks or months, and they can come and go without any clear pattern as to what could make them come and go.

Along with the red, itchy bumps, some people may experience something called angioedema. This is when there is swelling under the skin. It may be painful and itchy at the same time or just one or the other.

Treatment

CIU can be treated with behavioral practices (that relieve the symptoms or prevent possible causes), medications, or a combination of the two.

Behavioral practices to relieve symptoms and prevent possible causes of CIU include:

Clothing: Wear light clothes that fit loosely. Temperature: Use ice or cold cloths on the itchy bumps and stay cool. Soothing: Moisturize the skin with a gentle, unscented cream or lotion. Mental health: Relieve stress and practice relaxation. Allergens: Avoid possible allergens such as materials, plants, animals, and foods more likely to cause reactions.

Medications that may be used to treat CIU include:

Antihistamine: Medications used to treat allergies and reactions that work by blocking a chemical in the body called histamine Corticosteroids: Also called steroids, these are medications that work by reducing inflammation. Leukotriene receptor antagonists: Also called leukotriene modifiers, these are medications that are used to block chemicals in the body called leukotrienes that are released during allergic reactions. Immunomodulatory therapy: Also called immune system modulators, these are medications that calm the immune system to decrease reactions.

Does Chronic Idiopathic Urticaria Ever Go Away?

CIU does go away, but the symptoms may come and go for months or years. The medications used to treat this condition do not cure it. Instead, they decrease the reaction and relieve the symptoms until they go away. Sometimes people with CIU are able to find the cause and prevent future outbreaks.

Summary

Chronic idiopathic urticaria (CIU), or chronic spontaneous urticaria (CSU), is a condition that involves red, itchy bumps on the skin. It is more commonly known as hives with no known cause and lasts more than six weeks. CIU may be caused by an allergic reaction to things such as foods, medications, or plants.

There is no way to know how long it will last. It does eventually go away, but the symptoms can come and go for months or years. Treatment helps to provide relief. Anyone experiencing CIU should contact a healthcare professional for support.

A Word From Verywell

Suspecting or being diagnosed with hives can be uncomfortable and challenging, especially when the symptoms are long-term and there are no known causes. If you or someone you know is experiencing CIU, help is available. It is possible to receive treatment and recover. Reach out to a healthcare professional such as a primary care provider for support.