Allergens are either proteins or large chemical structures. They are large in the sense of their molecular weight but in fact are so small they can not be seen with the eyes! The have the ability to stimulate the immune response strong enough to cause a reaction and develop an immune memory. Which means when the allergen enters the body again it would remember it! With some allergens the immune systems develops with time and they stop reacting to them. Allergens enter the body through the nose, lungs, skin, digestive system and veins. Skin in these areas is the first line of defense. Hence its important to treat allergy inflamed skin.
Examples of allergens:
- Inhaled: the allergen enters through the nose and breathing. They cause symptoms in allergic rhinitis, conjunctivitis, sinusitis and asthma. examples include dust mites, pollen (grass/trees) , animals (cats, dogs, birds), fungal spores & insects (e.g cockroaches).
- Food: food enters the body through eating but also through the skin and inhalation. The reaction can be mild or life threatening like in anaphylaxis. Any food can cause allergy but nine food items make the majority of reactions. These include: cow milk, egg, soy, wheat, peanut, sesame, fish, shellfish, & nuts.
- Insect venom: such as bee venom and ants.
- Drugs: such as antibiotics (penicillins, cephalosporins).