What are the allergic diseases, and how common are they?

What are the allergic diseases, and how

?common are they

The primary allergic diseases include allergic asthma,

allergic rhinitis, atopic dermatitis, anaphylaxis, and food

hypersensitivities (Table 2).

Asthma is a disease of the lungs in which the bronchial

mucous membrane is chronically irritated and inflamed.

This inflammation makes the airways more hyperreactive

to a variety of provocative stimuli, including allergens,

cold air, exercise, and viral infections, leading to bronchospasm.

Typical symptoms include wheezing, chest

tightness, cough, and shortness of breath, which may

occur episodically or continuously. The disease is diagnosed

by history, findings on examination, and pulmonary

function testing.

Allergic rhinitis (to be discussed in greater depth later)

is similar to asthma, in that it represents mucosal inflammation

of the nose. The most common symptoms are

nasal congestion, sneezing, itching, and discharge. The

diagnosis of rhinitis is based primarily upon the history

and physical examination.

Table 2 Primary Allergic Diseases