Some things that are typically harmless to most people may cause an abnormal immune system reaction in some people. Such things are known as allergens. What happens is that the person’s immune system wrongly believes that such substance is harmful to the body and so takes necessary steps to safeguard body against those substances. Allergens could be certain foods, dust, pollen, medicines,…In its attempt to protect the body, the body’s immune system produces IgE antibodies to that allergen. IgE antibodies then cause certain cells in the body to release chemicals into the bloodstream. One such chemical is histamine.
Histamine may then act on the person’s eyes, nose, throat, lungs, skin or gastrointestinal tract. This may lead to symptoms of the allergic reaction. Any future exposure to the same allergen will result in same antibody response. This will repeat whenever the person comes into contact with allergen. Allergic reactions could range from the milder one like a runny nose, to severe one like difficulty in breathing. For example, an asthma attack, is often an allergic reaction to something that is breathed into the lungs in a person who is susceptible. In some cases reaction could be very severe like difficulty in breathing, difficulty in swallowing, swelling of the lips, tongue and throat or other parts of the body, and dizziness or loss of consciousness. Such severe reaction is called anaphylaxis. Here the triggering substance could be a peanut or any such thing. Usually the anaphylaxis reaction occurs within minutes after exposure to the triggering substance , but sometimes it could take long time in hours. There is a silver lining in the clouds here. Anaphylactic reactions are rare and can be treated successfully by proper medical procedures.
The cause of allergies is often hereditary, i.e. it can be passed through one’s genes. However, even if a parent has allergy, it is not for sure that the sibling too will suffer from that allergy. It only means that the chances of the sibling having that allergy are higher.
For treating allergies medications such as pills or nasal sprays are available. However, these medications are not a cure and can’t make you totally immune to allergies. They can only control symptoms like sneezing, headaches or a stuffy nose. One common medication is a shot of epinephrine. Epinephrine is a fast-acting medicine that can help offset an anaphylactic reaction. Allergen immunotherapy is also available. However this is available only for allergens that are breathed in like pollen or pet dander. It is not available for food allergies. This therapy tends to enhance a person’s tolerance to allergens and so results in less severe symptoms. For those suffering from allergy to bites and stings, venom immunotherapy is also available.