Immediate hypersensitivity to common food allergens: an investigation on food sensitization in respiratory allergic patients of Calcutta, India

BACKGROUND : Food allergy may be defined as an immunoglobulin E-mediated immune response to food proteins. Such studies have previously not been done in Calcutta, India. The present study was therefore undertaken to record the sensitivity to commonly consumed foods in patients with allergic rhinitis and asthma. MATERIALS AND METHODS : A survey of 800 patients (410 males and 390 females) reporting to the Allergy Unit of the Institute of Child Health, Calcutta, were selected for the study conducted from May 2006 to April 2007. Respiratory allergic patients in the age group of 5 to 60 years were evaluated using a standard questionnaire, and skin prick test was performed using common food and aeroallergens. RESULTS/CONCLUSIONS : Out of the 684 patients with a history of food allergy, most of them, that is, 338, are in the age group 16 to 40 years, 192 of them were in the age group 41 to 60 years, and 154 were in the age group 5 to 15 years. Most of the patients with food allergy had asthma (65.05%), rhinitis and asthma (20.03%), and skin allergies (4.97%), such as itching, eczema, and urticaria. The foodstuffs that were found to elicit symptoms of hypersensitivity were egg, milk, wheat, pulses, vegetables, fishes, and fruits.The patients aged between 16 and 40 years (male-female ratio, 1:1.19) were mostly sensitive to prawn, brinjal, banana, ladyfinger, papaya, wheat, and egg. The age group 41 to 60 years (male-female ratio, 1:1.04) had high skin reactivity to brinjal, egg, banana, fish, and Phaseolus mungo. Patients younger than 16 years (male-female ratio, 1:1.33) were sensitized to brinjal, prawn, banana, spinach, and egg. We observed that food hypersensitivity also reflects different genetic factors and variations in cultural and dietary habits of each individual.