Do allergic reactions trigger out of nowhere? It could be a dead mosquito

NEW DELHI: When alive, mosquitoes are a dreaded nuisance, transmitting many diseases through their bites. But they are no safer dead. The disintegrated portions of the dead pests, according to a study by Delhi University’s Vallabhbhai Patel Chest Institute, are the second-most common cause of allergic reaction in patients suffering from asthma and allergic rhinitis.

Dr Raj Kumar, study leader and head of pulmonary medicine at VP Chest Institute, explained that when mosquitoes shed hair, saliva or faecal matter, these disintegrated and became part of the air that is inhaled.

“Asthma and allergic rhinitis patients suffer from an aggravation of symptoms when they inhale mosquito-affected air because of their high sensitivity,” Kumar said, adding that families of such patients should ensure that house is cleaned properly to make it insect-free.


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Having conducted the skin prick test on more than 4,000 asthma and allergic rhinitis patients to check sensitivity of aeroallergens between August 2008 and July 2016, Kumar said the data showed “insects were the most common aeroallergens at 39%, followed by various types of house dust mites (12%), weed pollens (12%), dust (11%), fungal spores (6%) and tree pollen (6%), among others”. He added, “Among insects, we found mosquitoes (31%) were the most common allergens after cockroaches (49%).”

According to an editorial published in the Indian Journal of Chest Diseases and Allied Sciences, allergic reactions occur when a person’s immune system reacts abnormally to normally harmless substances, present in the environment. Allergic rhinitis, which is characterised by sneezing, is one of the most common allergic diseases affecting 10% to 25% population and a major reason for visiting primary care physicians.



Asthma is a common, chronic inflammatory disease of the airways that affects people of all ages. The prevalence of asthma has been estimated to be 3-38% in children and 2-12% in adults, being the commonest chronic disorder among children.

In the VP Patel Chest Institute study, doctors said the age group of patients suffering from asthma or allergic rhinitis or both ranged from 2 to 82 years. The maximum numbers of patients (34%) enrolled were between the ages of 20 and 29 years.



Explaining why the study was important, Kumar said, “Allergic reaction is a major reason for loss of productivity among the young. It is important to know the key allergens and how to stay away from them.”