Allergens

Research is still being conducted as to what causes allergies and if they can be prevented.  For now the best offense is still a good defense—try to stay away from any known allergens and have a detailed action plan in place along with appropriate medication to use in case of a reaction.  Undergoing a desensitization program such as for stinging insect allergies may also be a good idea to discuss with a medical professional.

Depending on the type of allergy a variety of things can be done to help with diagnosis including skin testing, blood testing, challenge testing, patch testing and elimination testing.

Skin test.  The skin test involves pricking or injecting small amounts of allergens onto the back or inner forearm and waiting approximately 15 minutes to see if an allergic reaction such as inflamed skin or hives occurs, thus indicating an allergy.

Blood test.  The blood test generally measures the amount of IgE in the blood that reacts with the specific allergen being tested.  IgE is an antibody produced by the immune system in response to allergic sensitization.

Challenge test.  A challenge test consists of a suspected allergen being inhaled or eaten.  It is usually only conducted for food and medication allergies and always must be well supervised by a doctor in case of severe reaction.

Patch test.  In a patch test, various possible allergens are applied to areas of a person's back and then held in place with adhesive for two days.  This is mainly used to determine causes of skin rashes or contact dermatitis.

Elimination test. The elimination test involves the individual removing foods or medications that are suspected allergens from his or her diet to see if there is an improvement.  If there is, then the food or medication is reintroduced to see if the problem arises again.

Allergies are generally believed to be caused by a combination of genetics and the environment.  If both a person's parents have allergies, the child is at a 50 percent greater risk of having allergies as well.

Good to Know

While a person can inherit the genetic tendency to have an allergy from his or her parents, the exact allergen itself is not inherited.

Allergens (i.e., the substances that cause a reaction) definitely vary by individual but there are certain ones that are the most prevalent.  They include foods and medications as well as insect bites or stings; also mold, pollen, dust and pet dander.  Some people can even be sensitive to specific kinds of jewelry and cosmetics.

Airborne allergens.  Airborne allergens such as dust, pollen, mold and animal dander can cause nasal congestion and itchy, watery eyes and/or trigger asthma.  For more information, visit the American Academy of Allergy Asthma & Immunology (AAAAI).  The following links are information AAAAI has for congestion and mold allergies. 

Food allergens.  Common food allergies include peanuts, tree nuts, eggs, milk, soy, fish and shellfish among others.  Symptoms are often digestion-related such as stomach pain or cramps, diarrhea or vomiting.  Hives and swelling can also result.  Sometimes these allergies are found in children but over time they can be outgrown. For more information, visit the American College of Allergy, Asthma & Immunology (ACAAI) and The Food Allergy & Anaphylaxis Network.

Medication allergens.  Individuals can be allergic to a variety of medications but some common ones include antibiotics such as penicillin, aspirin and ibuprofen.  For more information, visit the AAAAI.

Contact allergens.  Exposure to latex and some metals, particularly nickel (found in many pieces of jewelry and even clothing snaps and clasps) are two common triggers.  Rashes, itching, blisters and/or hives are frequent symptoms.  For more information on latex, visit AAAAI and the American Latex Allergy Association.  For skin contact allergies (including nickel and other metals), here is information from American Academy of Allergy Asthma & Immunology.

Insect stings.  Stings from insects such as wasps, yellow jackets, hornets, honey bees and others can cause allergic reactions.  For more information, visit the American College of Allergy, Asthma & Immunology.

Good to Know

People should always listen to their bodies.  Just because a suspected allergen isn't on the "most common" list doesn't mean it doesn't exist.

Beware of “exercise anaphylaxis.”  While this condition is rare, it can happen when exertion triggers an allergic reaction.  It does not happen every time a person works out but can be brought on by the combination of physical activity and another condition including but not limited to a particular food eaten, medication taken, temperature, humidity, season, etc.