Allergies Health Article

Asthma

Asthma is a chronic, reversible respiratory disorder caused by obstruction and swelling of the airways to the lungs. An asthma attack begins when the muscles surrounding the bronchial tubes go into spasm and the tubes become narrow. This stimulates increased mucus production, further blocking the airway, and, finally, inflammation and swelling, which cause even more congestion and discomfort. Symptoms include coughing, wheezing, shortness of breath, fatigue, anxiety, and tightness in the chest. Of the 9-10 million Americans affected by asthma, about half are children under the age of 16. Although asthma is considered an allergy, it is triggered by a variety of both allergic and non-allergic reactions. Some activities that contribute to non-allergic reactions include laughing, crying, and exercises that produce rapid breathing. Other non-allergenic irritants are tobacco smoke, air pollutants, paint, insecticides, and other chemical substances. Allergens that trigger asthma include pollen, animal dander, dust, and foods.

Like other allergies, asthma can be controlled by a combination of avoiding reaction-producing substances, using medications that can prevent attacks or lessen their severity, and administering allergy shots that can, over time, strengthen the body's tolerance to allergens. More than half of all asthmatic children outgrow the condition completely, while another 10% improve to the point where they have only occasional asthma attacks as adults.

Skin allergies

There are three main types of skin allergies: eczema (atopic dermatitis), contact dermatitis, and hives (urticaria). Eczema, which is mainly a condition of infancy and childhood, generally occurs in a cycle that begins with dry, itchy skin, followed by inflammation, "weeping," and crusting, all produced by scratching. At the chronic stage, the affected skin area becomes thickened, leathery, and scaly. Eczema appears most often on the cheeks, ears, and neck, and the inner folds of elbows and knees, but it may affect other parts of the body as well. It is commonly found in allergy-prone families and usually outgrown by the age of six. Aside from avoiding allergens, the most important treatment is to keep the skin lubricated by using hypoallergenic lotions and gentle soaps. (For extremely dry, sensitive skin, Cetaphil lotion may be used as a cleanser instead of soap.) Eczema tends to be aggravated by sweating, food allergies, infections, and emotional stress.

Contact dermatitis—as its name suggests—is caused by topical contact with an irritant, which can be a plant (such as poison ivy), chemical, metal, cosmetic preparation, or other substance. Diaper rash is the most common form of contact dermatitis in infants. The most effective treatment is to avoid contact with known irritants. Calamine lotion, hydrocortisone ointments and creams, and other preparations can help alleviate itching once symptoms occur.

Hives (urticaria) are red, itchy blotches of varying size that can occur anywhere on the body but are especially common on the stomach, chest, arms, hands, and face. A related condition is angioedema, a swelling that may affect the eyelids, lips, mucous membranes, genitals, and other areas. Both of these conditions are treatable with antihistamines, epinephrine, and cromolyn. They are usually acute rather than chronic, although they can sometimes persist for weeks. Intractable cases may be treated with oral cortisone, which should be used sparingly and only as a last recourse because of its side effects.