Urticaria, or hives, are itchy red welts affecting about 20% of people at some point in their lives. Hives often indicate an allergy to a food or medication and will subside on their own.

Chronic Idiopathic Urticaria (CIU) occurs when hives repeatedly appear without apparent cause. It affects less than 1% of people. Those diagnosed with CIU have daily (or near-daily) outbreaks for six weeks or more, with no discernible reason. Each episode usually lasts no more than 24 hours, but new hives may appear.

Doctors don’t know what causes CIU. They know it is most common in adults ages 20-40 and that the immune system likely plays a part. Research shows that hormonal problems, cancer, and thyroid disease occur in some people experiencing CIU.

A CIU diagnosis involves testing for conditions that could cause hives and interpreting personal history. Mapping hive outbreaks, other symptoms experienced, diet, medications, pets in the home, and other lifestyle factors could indicate an allergy. If this doesn’t uncover allergic reactions or any condition associated with hives, CIU is the likely diagnosis.

CIU is not contagious or dangerous and usually goes away. Most experience CIU anywhere from 1-5 years, though that is small comfort while you are experiencing symptoms. Known triggers include:

• Temperature changes
• Exercise/sweating
• Tight clothing
• Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen
• Alcohol
• Stress/anxiety
• Sun exposure

CIU treatment usually starts with over-the-counter antihistamines. If they don’t help, H2 blockers to halt histamine production or oral corticosteroids such as prednisone are next.

Antidepressants and immunosuppressants have also been successful in treatment. Monthly omalizumab (Xolair) injections are effective but also very expensive. These treatments may relieve your symptoms, but they are not a cure. Hives may reoccur when you stop using medications, until the condition recedes on its own.