Respiratory diseases and food allergy.

Both upper and lower respiratory tracts can be affected by food allergy. Manifestations in either may be exclusively due to food allergy (common in infants) or may result from the combined effects of food allergy plus another defect such as gastroesophageal reflux, a congenital defect of the heart or tracheo-bronchial tree, an immunodeficiency syndrome such as isolated IgA or IgG4 deficiency, or a concomitant inhalant allergy. Chronic rhinitis is the most common respiratory tract manifestation of food allergy. When it occurs in conjunction with lung disease, it may be a helpful indicator of activity of the allergic lung disease and of the patient's compliance in following a specific diet. Recurrent serous otitis media may be solely or partially due to food allergy. Large tonsillar and adenoid tissues, sometimes with upper airway obstruction, may be caused, or aggravated by, food allergies. Lower respiratory tract disease manifested by chronic coughing, wheezing, pulmonary infiltrates, or alveolar bleeding may also occur. Lower respiratory tract involvement is generally associated with a greater delay in onset of symptoms and with a larger quantity of allergen ingestion than chronic rhinitis. Food allergy should be considered when there is a history of prior intolerance to a food in childhood or of symptoms beginning soon after a particular food was introduced into the diet. It is an important consideration in patients who have chronic respiratory tract disease which does not respond adequately to the usual therapeutic measures and is otherwise unexplained.(ABSTRACT TRUNCATED AT 250 WORDS)