Hives and Angioedema
Hives can be a very distressing form of allergic reaction. A hive is an area of swollen skin (wheal) surrounded by red skin (flare). They often are itchy. A single hive can last just a few minutes or for days. Hives can occur as a single episode or recur for years.
The same kind of reaction can occur deeper in the skin causing swelling. This is angioedema. Angioedema of the face and hands is usually more dramatic than other parts of the body because a little swelling here is easily noticed.
With hives and angioedema, very active materials (mediators) are released by cells of the immune system and cause certain blood vessels to leak fluid. This fluid leaking into the tissue causes swelling. Reflexes from nerves cause surface blood vessels to enlarge and carry more blood, making the characteristic redness. These “mediators” also stimulate nerve endings, causing itching or burning.
What Causes Hives?
There can be many causes of hives. Common causes include foods, insect stings, antibiotics, animal contact, pressure, cold and viral infections. In rare cases, endocrine problems, water, heat, cosmetics, light, bacterial infections and tumors can be the cause. Emotional factors and anxiety can make hives worse. It is important to note any new medications, exposures or medical conditions that may have occurred when the hives started. Your doctor can help, but you are the best detective. The longer hives are persistent, the less likely it is that you’ll be able to remember the possible cause.
Rarely, swelling can occur in the throat, blocking breathing. A drop in blood pressure can result from a severe allergic reaction. Use of adrenaline may be necessary in this situation. An Epi Pen should be used in such a severe condition before or while heading to the nearest emergency facility. Those who suffer hives with cold exposure should avoid swimming in cold water and should never swim alone.
Treatment for Hives
Fortunately, the treatment of hives has improved over the past few years. Antihistamines have usually been the most effective medications for this problem. In severe cases, injectable medications may be used in treatment.
Treatment for hives begins with identifying the cause of the allergic reaction, so pay attention to how and when hives develop.