Earlier studies reported the pollen of Partheenium, Albizia, Cassia, Ageratum and Ricinus, and dust mites D.pteronyssinus and D.farinae to be the commonest airborne allergens (Anand P and Agashe SN, Ind Journal Otolaryngol, Vol 36, no 2, 1984 and Channabasavanna GP, Final Report: Research Project H Dust Mites, DST, Gov Ind June 1983).
Present study involved skin prick tests done on 134 patients of respiratory allergy with standard protocol. 82 male and 52 female patients with moderate–severe persistent allergic rhinitis, rhinoconjunctivitis and asthma were the study subjects with mean age of 30.2 ± 13.8 years. 30 were asthmatics and 64 were asthmatics with rhinitis.
Cynodon dactylon (22.4%) and Pennisetum typhoides (5.9%) are the commonest grass pollen allergens. Artemesia scoparia (15.7%), Partheenium hysterophorus (8.9%), Ageratum conyzoides (8.2%) and Helianthus annuus (8.2%) are the commonest weed pollen allergens. Prosopis juliflora (14.2%), Cassia siamea (10.4%) and Ricinus communis (8.9%) are the commonest tree pollen allergens. D.pteronyssinus (58.9%) and D.farinae (47%) are the commonest indoor allergens.
House dust mites have remained the predominant indoor allergens even now. Present study shows significant change in the type of pollen allergens. Cynodon, Artemesia and Prosopis have replaced Partheenium and Albizia as the predominant allergens in two decades. Helianthus annuus and Pennisetum typhoides, which were insignificant in the past, have emerged as significant allergens. Molds as airborne allergens have become very insignificant.
Bangalore has grown enormously in the last two decades. Innumerable vacant lands and swampy areas covered by weeds like Partheenium, have become buildings. Helianthus is cultivated on a large scale all around as a commercial crop. Large outskirts around the city have become residential and, office and commercial hubs resulting in a considerable change in pollen allergen flora. This change in the pollen allergen profile is an important guideline for allergy diagnosis and immunotherapy. This evidence may have significant application to the management of allergy patients in other major cities of India like Hyderabad, Chennai, Delhi, Mumbai and Kolkata as well.