Question

In the metropolitan cities of India, many children are suffering from allergy/asthma.

What are the main causes of this problem.

Give some symptoms of allergic reactions.

Answer 1

Allergy

Allergy is a hypersensitive reaction to specific antigens, also termed allergens, present in the environment. Examples include pollen, dust etc.

Predisposing factors in children

• Genetic factors: The susceptibility to allergic reactions can be largely due to genetic factors.
• Reduced pathogen exposure: Since children are protected from most pathogens in cities, the strength of their immune system is low.
• Industrialisation: Cities have greater amounts of soot, smoke from automobiles, causing children to be more prone to the exposure of allergens.

Main causes of allergy

Compared to rural settings, air pollution is much highter in metropolitan cities. The presence of dust, smoke and soot in the environment causes children to have allergic rhinitis.


Symptoms

Symptoms of allergies include sneezing, running nose, watery/red eyes, difficulty in breathing etc. Hives, itchy skin, and rashes are some symptoms of skin allergy.

Underlying mechanism

When allergens enter the body, they crosslink the immunoglobulins (IgE) on the surface of the mast cells. This results in the release of histamine and other chemicals from the mast cells and results in an allergic reaction.
These histamines can cause the inflammation of the nasal mucous membranes resulting in running nose or sneezing.