Urticaria is the medical term for hives. It causes bumps or raised patches to appear on the skin. Chronic idiopathic urticaria is the name for hives that occur at least twice a week and last more than 6 weeks.

Hives are patches of skin or bumps that can be very itchy and may appear swollen. Chronic idiopathic urticaria causes a person to develop hives that last for a prolonged period.

In this article, we discuss the definition of chronic idiopathic urticaria and discuss its symptoms, treatment options, and causes.

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Urticaria is the medical term for hives. Idiopathic is a term medical professionals use to describe a condition that has no identifiable cause. Some medical professionals may also refer to idiopathic urticaria as spontaneous urticaria.

Most people’s idiopathic urticaria causes hives that last for a few minutes to a few hours. Most hives clear up within 24 hours.

If a person has hives that continue to appear on a person’s skin for 6 weeks or longer, then they likely have chronic idiopathic urticaria. Chronic is a term medical professionals use to describe a condition or disease that is persistent or long lasting.

Chronic idiopathic urticaria causes a person to develop hives on their skin that are:

These hives may also appear on the soft and moist tissue that lines a person’s:

  • eyelids
  • mouth
  • other areas

Common symptoms of chronic idiopathic urticaria include:

  • a rash of smooth, raised welts that differ in size and shape
  • hives that cause:
    • an itching sensation
    • a burning sensation
    • a stinging sensation
  • hives that feel warm to the touch
  • hives that run together and cause a large, raised patch to develop

Some people have hives that only appear in a few places. It is also possible for hives to cover a large portion of the body.

If a person has darker skin tones, their hives are usually the same color as their skin. They may also be slightly darker or slightly lighter than the person’s natural skin color.

If a person has a light or medium complexion, they will often develop hives that are red or pink. In this case, if a person presses on their hives, the red or pink color will often disappear and return when they stop pressing.

If a person develops swelling in their mouth or throat, they should seek immediate, emergency medical care. A person should also receive immediate medical care if they develop hives and have difficulty breathing.

Medical professionals do not fully understand what causes chronic idiopathic urticaria. Some medical professionals believe it occurs due to a dysfunction in the autoimmune system.

According to the American Academy of Dermatology Association (AAD), hives develop when the body releases histamine. Histamine is a chemical that plays a role in the modulation of allergic reactions.

When the immune system recognizes a threat, it releases histamine and other chemicals. This can help protect a person from becoming seriously ill. In some people, the immune system mistakenly releases histamine when there is no threat present. This is what happens when a person has an allergic reaction.

Common events that cause the body to mistakenly release histamine, causing hives, include:

  • allergic reactions
  • overreactions to:
    • heat
    • sweat
    • cold
    • sunlight
  • stress
  • pressure on the skin due to:
    • tight clothing
    • the light touch of straps and clothing
    • scratching

The AAD estimates that millions of people in the United States will develop hives during their lifetimes without understanding the cause.

A dermatologist will often diagnose chronic idiopathic urticaria simply by looking at the person’s skin.

They may also ask a person about their medical history, including if they have any allergies or if they have had any recent medical treatments, such as radiation therapy or a blood transfusion.

A dermatologist may also use other tests to confirm a diagnosis. These include:

During a skin biopsy, a dermatologist will remove a small part of the affected skin. They will then examine this sample under a microscope to confirm their diagnosis.

A dermatologist will often then try to determine what caused the condition. This is to help prevent the person from developing it again. They may ask the person:

  • how often they get hives
  • how long their hives have lasted
  • if their hives are itchy or painful
  • if they experience other symptoms when they develop hives, such as lightheadedness or nausea.

If a person has had hives for 6 weeks or longer, then a dermatologist will diagnose them with chronic idiopathic urticaria.

Hives usually go away on their own. This means the main goals for treatment of chronic idiopathic urticaria are:

  • to control the itch
  • to prevent new hives from developing
  • to avoid what causes the hives to develop

A dermatologist will tailor a person’s treatment plan to their specific needs. They may use one of the following medications to treat chronic idiopathic urticaria:

  • Soothing lotions or anti-itch creams: A dermatologist may suggest a Prax lotion or cream that can offer temporary relief from the itching sensation.
  • Antihistamines: Antihistamines are medications that can control itching and swelling.
  • Corticosteroids: If a person has severe hives, a dermatologist may prescribe corticosteroids to reduce inflammation and treat the itch.
  • Omalizumab: Omalizumab is a medicine a person injects. It can treat chronic hives. Dermatologists will often prescribe omalizumab if treatment with antihistamines has failed.
  • Light therapy: Light therapy is a noninvasive treatment that involves exposure to an artificial light source. A person may require several sessions of light therapy to help treat chronic idiopathic urticaria.

If a person develops hives, they may want to keep track of what they have eaten to see if they can determine what is triggering the hives.

For some people, reactions to specific foods may be triggering the hives. Some foods that contain possible triggers include:

  • peanuts and other nuts
  • eggs
  • shellfish

If a person has a latex allergy, then specific foods may also trigger their hives. These foods include:

  • bananas
  • chestnuts
  • kiwis
  • mangos

Other people may develop hives due to a reaction to certain additives present in foods, including:

  • colorings and preservatives
  • vitamins
  • supplements
  • spices

A medical professional may suggest a person get a skin prick test to help determine if certain foods are triggering their condition.

During this test, a doctor will place liquids containing certain foods on a person’s skin. They will then make a small prick in the middle of each sample so the liquid can penetrate the outer layer of the skin.

If a person has an allergic response to the liquid, then their skin will show a change of color and swelling. This will show which foods may trigger their hives.

Once a person is aware of which foods may trigger their hives, they should try to avoid eating them.

Chronic idiopathic urticaria is a condition that causes a person to develop hives that last for a prolonged period. A person has chronic idiopathic urticaria if they develop hives that last for 6 weeks or longer.

Hives are patches of skin or bumps. They can be very itchy and may appear swollen. Allergic reactions and reactions to certain foods or situations may trigger hives.

Hives usually go away on their own. People can treat their hives with medications that help reduce itchiness and swelling. These include soothing lotions or anti-itch creams, antihistamines, corticosteroids, and omalizumab.