By David J. Resnick, MD FAAAAI | Allergy/Immunology
What are hives or urticaria?
Hives is a condition that affects an estimated 20 percent of the population at one time or another in their lives. Hives is a rash that causes itching, followed by swollen and red welts. The itching may be mild or severe. The medical term for hives is urticaria. Hives may last for a few minutes, sometimes several hours, and even several weeks or months.
Hives are broken down to two types, acute and chronic. Acute hives last for six weeks or less. Chronic hives last more than six weeks. Most laypeople believe acute hives is mainly triggered by foods. The reality is that the most common cause of acute hives is an infection. After infections than foods and medications are the next most likely culprits.
When dealing with chronic hives, the cause will not be identified despite testing in most cases. This is called idiopathic hives. Forty percent of patients have antibodies (proteins) that attack the mast cell (allergy cell). This triggers chemicals such as histamine to be released which causes the hives and itching. It is also rare for a food to cause chronic hives. In most cases of chronic urticaria, the hives will gradually disappear over time.
What medications treat hives?
There are many different antihistamines that are used to treat hives. Some cause drowsiness, more than others. Over the counter antihistamines such as loratadine (Claritin), fexofenadine (Allegra) and cetirizine (Zyrtec) are less likely to cause drowsiness than Benadryl. Whatever is used does not permanently make the hives disappear. When the medications are discontinued the hives can return.
Many chronic hive patients fail routine therapy and then go onto using fancier medications such as prednisone and cyclosporine. These medications can work, but can have significant side effects. Recently the FDA approved Xolair as a treatment for chronic hives. This is an injectable medication that has been used for asthma in the past. The side effect profile is much better than prednisone, and cyclosporine. It works for most patients with chronic hives. This new use for Xolair gives hope to appropriate patients who can go for months or even years without receiving satisfactory itch and hive relief.
If you are a patient with hives, you can make an appointment with one of our allergist to discuss possible therapies.