Allergies and asthma are as similar as they are different

Inflammation...triggers...wheezing...congestion—they’re familiar terms among people who have asthma or an allergy. But, significant differences exist in the details of each term, depending upon its roots—asthma or allergy.

Allergies and asthma have several similarities. They both involve an inflammatory process that begins with an overreaction of the immune system, and many of the same substances that trigger asthma are also responsible for causing allergic reactions. In many cases, asthma actually is caused by allergies (allergic asthma). When a person with allergic asthma is exposed to substances such as pollen, animal dander, or mold, the exposure triggers a reaction. The person’s airways become swollen and inflamed—causing wheezing, coughing, and other symptoms of asthma.

But for all their similarities, allergies and asthma have important differences as well.

A shared pathway . . . to a point

In both allergies and asthma, the immune system releases molecules called antibodies to defend against substances that the immune system mistakes as harmful invaders—pollen, mold, or dust mites, for example. That release of antibodies prompts a series of reactions. For some people, those reactions include sneezing or watery eyes. For others, it’s itchy skin or closing up of the airways.

Yet whereas asthma affects only the airways, allergies may involve several parts of the body, such as the upper respiratory system, eyes, and skin. Asthma symptoms may stem from various substances that also set off allergy symptoms, but they also may be triggered by factors that have nothing to do allergies, such as exercise, cold air, viral infections, or gastroesophageal reflux disease (GERD, or acid reflux).

Drug treatment is not all for one or one for all

Some of the same medications prescribed for allergies are also used to treat asthma. For example, corticosteroids benefit both conditions: Nose sprays that contain corticosteroids relieve the nasal congestion of allergic rhinitis—better known as hay fever—by reducing inflammation. Creams containing corticosteroids soothe the inflamed skin of allergy-related dermatitis. And in a person with asthma, inhaled corticosteroids relieve inflamed airways.

Nevertheless, some drugs useful for people with allergies have no place in asthma treatment, and vice versa. For example, antihistamines are the cornerstone of allergy treatment, but do very little for asthma symptoms. And bronchodilators, which are essential to asthma treatment, aren’t prescribed for allergy symptoms.

From Coping