Pattern of Allergen Sensitivity among Patients with Bronchial Asthma and/or Allergic Rhinosinusitis in a Tertiary Care Centre of Southern India.

INTRODUCTION: The distribution of aeroallergens varies among various geographical areas of India and the knowledge of allergen sensitivity pattern in this part of Southern Indian (Karnataka) is limited. This data can provide clinically useful information and better understanding of common allergies prevalent in this area.

AIM: To study the pattern of allergen sensitivity among patients with bronchial asthma and/or allergic rhinosinusitis.

MATERIALS AND METHODS: In this retrospective study, patients diagnosed with bronchial asthma and/or allergic rhinitis who underwent skin prick testing, were included in the study. Patients who had taken drugs that could affect the test results, within one week prior to testing were excluded. Also, patients on long-acting oral antihistamines within four weeks of testing and pregnant women were excluded. A total of 64 antigens were used which included eight types of pollens, eight types of dusts, six types of fungi, eight types of insects, two types of danders, wool and 31 types of food items. Skin prick testing was done as per standard protocol.

RESULTS: Out of 2219 patients, 1193 (53.8%) were males and 1026 (46.2%) were females. The mean age of the subjects was 41.47 (±14) years. There were 740 (33.3%) patients diagnosed with bronchial asthma, 357 (16.1%) allergic rhinitis and 1122 (50.6%) had both bronchial asthma and allergic rhinitis. Overall the highest percentage of skin-prick test positivity was found among insect allergens (24.45%) followed by dust (24.21%), grass and tree pollen (20.57%), fungus (13.92%) and food allergens (9.28%), in that order. Among the individual allergens, the highest percentage of skin-prick test positivity was present in rice grain dust allergen (33.30%) and the least common was chicken allergen (4.40%).

CONCLUSION: Among the allergen groups, insects and dusts elicited the highest percentage of skin-prick test positive results. Whereas, among all the individual allergens rice grain dust elicited highest percentage of positives.