Name two allergic disorders.

Explanation

Allergy is the exaggerated response (hypersensitivity) of the immune system to certain antigens present in the environment. The substances which evoke such an immune response, are called allergens. The antibodies produced belong to IgE type. The allergens attach to the antibody bound mast cells and basophils. The complex ruptures to release histamine, an allergy mediator in secondary immune response. Common allergens are mites, dust, pollens, animal fur, etc. Sneezing, watery eyes, running nose and difficulty in breathing are the symptoms of allergic reaction. Symptoms are due to release of chemicals like histamine and serotonin from mast cells.
Prevention. The use of drugs like anti-histamine, adrenalinand steroids quickly reduce the symptoms of allergy. Protected environment provided in early life, make the children more sensitive to allergens, lowers immunity and hence, they suffer from allergies and asthma.
Some Allergic diseases are-Hay fever, Asthma, Anaphylaxis, etc.