About 20 percent of people develop hives â€” itchy red or white welts on the skin â€” at some point in their lives, according to the American College of Allergy, Asthma & Immunology (ACAAI). Most often these hives are acute, meaning that theyâ€™re a temporary allergic reaction â€” to a trigger such as food, medication, or an insect bite â€” that usually lasts only a few hours. But for some people, the welts donâ€™t go away and have no known cause, in which case they're known as chronic idiopathic hives, or chronic idiopathic urticaria.
Chronic hives last at least six weeks and can recur over months or even years. Individual hives may last continuously throughout the day or may fade away only to reappear a short time later. Although the exact cause of chronic hives often canâ€™t be identified, the skin reaction occurs when the immune system releases histamine in response to an allergen or trigger.
Signs and Symptoms of Chronic Hives
â€œThe signs and symptoms of chronic hives are essentially the same as those of acute hives: red [or white] raised itchy lesions that can vary in size and can occur on any part of the body,â€ says Andrew Murphy, MD, the founding chief of the allergy section of PENN Medicine Chester County Hospital and a fellow of the American Academy of Allergy, Asthma, and Immunology. â€œThe main distinction is that chronic hives are present for at least six weeks.â€
Physical signs of chronic hives to look for include:
- Groups of red or white welts that can appear anywhere on the body but typically develop on the face, trunk, arms, or legs
- Mild to severe itching
- Swelling that causes pain around the affected area
- Welts that vary in size, change shape, or fade and reappear
- Flare-ups brought on by triggers like heat, exercise, or stress
About 30 percent of adults who have chronic hives also experience angioedema, deep swelling under the skin that often occurs around the eyes, lips, and cheeks, according to the Asthma and Allergy Foundation of America.
â€œItâ€™s not unusual to not find a cause for chronic hives. In fact, most of the time a cause for chronic hives is not identified,â€ says Dr. Murphy. While the trigger may be difficult or even impossible to identify, chronic hives may be linked with more serious health conditions, including thyroid disease, hormonal problems, or in very rare instances, cancer. When the cause cannot be determined â€” in which the condition is known as chronic idiopathic hives â€” about half the cases are associated with some kind of immune disorder, according to the ACAAI.
Chronic hives may also result from a reaction to medication. â€œMedications may be a potential cause,â€ says Murphy, â€œparticularly if a new medication has been started in the weeks prior to the onset of the hives.â€
Although itâ€™s possible for food to be a cause of chronic hives, it's not likely, says Murphy. â€œFood reactions typically occur very quickly after ingestion. Similarly, insect bites would cause an acute reaction that would resolve in a short period.â€
Other potential causes of chronic hives include:
- Bacterial and viral infections
- Physical stimuli, such as heat, cold, sunlight, pressure, or exercise
- Pet dander
Diagnosing Chronic Hives
In an effort to determine the cause of persistent, itchy hives, your doctor will perform a physical exam and review your medical history. â€œWhile typically no cause is identified for chronic hives, the history and physical exam are necessary to rule out such rare causes of chronic hives as vasculitis (inflammation of blood vessels), rheumatologic disease, chronic infections, thyroid disease, and other endocrine disorders, like cancer,â€ says Murphy. â€œRoutine allergy skin tests and blood tests may be done if thereâ€™s a specific hint in the history that would suggest an issue.â€
Your doctor may recommend that you keep a diary of your daily activities to help pinpoint a cause. If itâ€™s possible to identify a trigger, avoiding that trigger can help you prevent the recurrence of chronic hives. Your doctor may also prescribe medication to help you control and better manage your symptoms.
Treating Chronic Idiopathic Hives
Various medications have been designed to block the immune response that causes hives. Learn about your treatment options.
Living With Chronic Hives: Sierraâ€™s Story
Chronic hives are unpredictable, and symptoms can come and go for years. One New Yorker knows this all too well, and she's found ways to cope.