Hives, an allergic skin disorder, are raised round pink or red lesions with flat tops. Itchy and warm to the touch, they range in size from ¼ to ½ inches or sometimes larger. More severe hives, called angioedema, tend to be larger and linked to one another; they also penetrate more deeply into the skin. In rare cases, hives can develop in the mouth and throat, obstructing breathing or heralding a life threatening anaphylactic reaction. Most often, hives are caused by food allergies, with the most frequent culprits being chocolate, shellfish, nuts, eggs, strawberries and other fruits, as well as food preservatives, dyes, and other food additives. Some people develop hives after eating even a minute amount of the offending food, while others break out only when they overindulge in it. Certain drugs, especially penicillin, can also cause hives, as can aspirin and numerous other medications. There are people who develop hives in response to contact with cats or other animals, insect bites, extreme temperatures, or exposure to detergents or dry cleaning chemicals on clothes. In others, hives appear as part of a photosensitive reaction to sun exposure, especially if certain medications are being taken. The role of stress in hives has been much debated; some allergists say it can be a factor, but other experts dispute this claim.
Other Causes of Hives
In unusual cases, hives may be the first sign of a viral infection, such as hepatitis, rubella, or mononucleosis, as well as serious illnesses, such as lymphoma, lupus, hyperthyroidism, or cutaneous vasculitis. In rare instances, chronic angioedema is caused by a hereditary enzyme deficiency.
Types of Hives
There are several types of hives, and you should at least have an idea about them, so here is a list to help you:
- Normal (ordinary) hives
- Drug-induced hives
- Chronic hives
- Physical hives
- Acute hives
Finally, the best thing that you can do when you notice hives appearing again is to remember what sort of substances you have been around for the last couple of days because this might help the doctor accurately diagnose your condition and treat it efficiently. In any case, try not to scratch too much and see a doctor as soon as possible.
Diagnostic Studies And Procedures
Hives are easily self diagnosed on the basis of their appearance and feel. If you have recurrent hives but do not know what triggers them, skin tests performed by an allergist can help identify the offending substances. If allergies are not responsible for persistent hives, more extensive testing will be necessary to identify their cause.
Hives usually disappear on their own within one to seven days of their development. In the meantime, if the cause is not obvious and you are taking any medication, call your doctor to ask if you should discontinue it. To alleviate itching and discomfort, a physician may prescribe an antihistamine in prescription strength, such as diphenhydramine (Benadryl), cyproheptadine (Periactin), or hydroxyzine (Atarax). In mild cases, a nonprescription antihistimine may be sufficient. (Caution is needed when taking these drugs because they produce drowsiness.) If hives are widespread and severe, a doctor may prescribe a corticosteroid drug such as prednisone. If symptoms of an anaphylactic reaction develop , or if there is a “lump” in yom throat or a choking sensation, get immediate help by calling an ambulance or having someone take you to the nearest emergency room. In such a situation, an injection of epinephrine (adrenaline) is life saving.
Herbalists recommend a tea made from Urtica dioica, the stinging nettle plant, as a natural alternative to antihistamine drugs. This herb is also available as capsules made from a freezedried extract.
Bath additives can often help ease the itching and discomfort of hives. Try cornstarch, baking soda, or colloidal oatmeal. If you have hives that are induced by exposure to cold temperatures, you may be able to build up your tolerance by taking a cool shower once or twice a day.
Try to identify the foods that you believe trigger your hives and then eliminate them from your diet. Follow up by returning the suspected offenders, one at a time. If hives reappear, then you know you have correctly identified an offending food that you should avoid in the future.
- A topical treatment such as calamine lotion can ease the itching of hives, and an over the counter antihistamine can speed healing. If you suffer with chronic hives, your doctor may also recommend the following preventive measures:
- Avoid aspirin and other nonsteroidal anti inflammatory drugs, such as ibuprofen. These medications some times provoke hives and other allergic reactions involving the skin.
- Avoid these food additives: tartrazine, a common food and drug coloring; the food dye FD&C Yellow No.5, benzoate food preservatives; and the preservatives BHA, BHT, and nitrates.