Reasons for allergies
Environmental factors:
Pollen: Allergy occurs when pollen from certain plants reaches the lungs through the air (hay fever).
Dust mites: Microorganisms found in dust and mattresses in homes.
Pets: Animal hair, saliva, and skin scales can cause allergies.
Food allergies:
Some people develop allergies when they eat milk, eggs, peanuts, shellfish, and wheat.
Skin allergies:
Some soaps, detergents, cosmetics, certain metals (jewelry), and clothing can cause itching or swelling when they come into direct contact with the skin.
Insect bites: When a bee, wasp, or other insect stings, the venom enters the body and causes an allergic reaction.
Drug allergy: Some antibiotics (e.g. penicillin) or painkillers can cause allergies.
Other causes: Excessive air pollution, cigarette smoke, and cold weather (cold allergy) can also worsen allergy symptoms.
