Urticaria and Angioedema

Acute urticaria and angioedema
Acute urticaria and angioedema are hives and diffuse swelling which lasts less than 6 weeks. The most common causes of acute urticaria and angioedema are: drugs, foods, insect bites and viral infections. Treatment is aimed at avoiding the possible cause and use of antihistamines and/or corticosteroids until the lesions have resolved.

Chronic urticaria and angioedema
By definition, chronic urticaria and angioedema are hives and swelling that have lasted longer than 6 weeks. The most common causes of chronic urticaria and angioedema are: idiopathic, drugs, foods, allergies, infections, physical factors, infections, hereditary and systemic disease. Please note that "nerves" or stress are not usual causes of chronic hives.

• Drugs: Any drug including medication taken without a prescription such as aspirin and vitamins can cause hives. Even if a drug has been taken for years, it could be triggering this skin reaction.

• Food: Foods are usually not the cause of chronic urticaria but one should be suspicious of commonly eaten foods.

• Allergies: Allergies are usually not a common trigger of chronic hives. Hives which occur with symptoms of hay fever and/or asthma may have an environmental component and should be investigated.

• Physical factors: Physical factors such as scratching the skin (dermatographism) and pressure will cause hives. In some people, cold, exercise, or sunlight have been known to provoke hives.

• Infections: Hives commonly appear with underlying infections. In children, viral infections are frequent causes of urticaria. Hives have been reported with the onset of mononucleosis and hepatitis. Other infections have also been linked to causing chronic hives.

• Hereditary: Hereditary angioedema is a rare inherited disease which can cause chronic angioedema. Swelling can occur in the airways, face and extremities. Usually there is a family history. It has been demonstrated that a blood protein deficiency is the cause of this inherited illness.

• Systemic disease: Autoimmune disorders such as systemic lupus erythematosis and rheumatoid arthritis and endocrine disorders especially hyperthyroidism can cause chronic hives and/or angioedema. In rare cases, malignancies of the lung and colon have been reported as a cause.

• Idiopathic urticaria and angioedema: Studies have shown that over 80% of chronic hives and angioedema have no known demonstrable cause. The good news is that in about 50% of such patients will have resolution in a year or less and there is nothing seriously wrong with the patient's health.

How are hives treated?
If a cause is found for the hives, then treatment is directed toward eliminating it. Avoidance of the drugs, food or other provoking factors is recommended whenever possible. Since in most patients with chronic urticaria the condition is idiopathic, treatment consists of medication to control the hives and swelling until the condition resolves by itself. Antihistamines are used to treat recurrent episodes. Other medications may be added if the antihistamine is not controlling the symptoms. Oral coricosteroids such as prednisone should only be used as a last resort for chronic urticaria because their daily use can cause numerous unwanted side effects. It is important that the patient understand how frustrating this condition can be; however, it can usually be controlled through medications.

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