The main function of our immune system is defence against foreign substances. But when our immune system responds out of proportion to common and relatively harmless substances it is called Allergy.
The substances which cause this allergic reaction are known as Allergens. Our body produces antibodies in response to that and they are known as Antigens.
Antibodies protect our body against foreign invaders by fighting against them. They are Immunoglobulins, commonly; IgG, IgM and IgA are antibodies which are produced in reaction to bacteria or viruses.
But Immunoglobulin IgE is produced in response to allergic reaction in larger amounts. Immune system also produces T cells especially against allergens which affect skin. The reaction of these IgE antibodies with the antigen produces Histamine.
Allergies are more common and severe when body's defence system is weak, like when suffering from chronic illness or during pregnancy. Allergies are more common in people with weak immunity or in immune compromised people.
Any person can get allergy any time. Allergies can completely settle down with time and can recur again. But they can persist for lifetime too. Common allergic conditions are hay fever, allergic rhinitis, allergic asthma, atopic dermatitis .
Common Allergic Triggers-
Dust mites, house dust, moles, pollens (from tree, grass or weeds), animal hair, fur, insect bites, bee stings, tree pollen, smoke, pollutants, strong smell, latex, cockroaches.
Peanut, eggs, cow milk, soy products, fish, shellfish (seafood), nuts (pecan, pine nut, walnut, pistachio ) , cheese, sesame seeds.
Medicines like penicillin, ibuprofen, Sulphur drugs.
Allergies can subside, person may get over them with time but they can return.
