What is the term for the exaggerated response of the immune system to certain antigens present in the environment?

Which drugs quickly reduce the symptoms of allergy?

Common symptoms of allergy are:

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.

Which of the following secretions from mast cells induces an acute response in an allergy?

$A$ person shows symptoms like sneezing,watery eyes,running nose,and difficulty in breathing upon exposure to certain substances in the air. Which type of antibody is produced during such a condition?