ARE YOU ALLERGIC TO NUTS?
How is nut allergy diagnosed?
Medical history and examination
Your doctor may suspect that you have a nut allergy from your symptoms. Your doctor may then ask a lot of questions. For example, the amount and type of food that you ate which caused a reaction, how quickly the symptoms started, how severe they were, how long they lasted, etc.
Skin prick test
A skin prick test may be done to help confirm the allergy. For this test, a drop of nut extract solution is placed on the skin, usually on the forearm. Then, a needle prick is made through the drop. This is usually painless as just the very surface of the skin is pricked. However, it is enough to let a tiny amount of solution into your skin. If a reaction occurs, it happens within 20-30 minutes.
A reaction is considered to be 'positive' when the skin under the solution becomes red and itchy. A white, raised swelling called a wheal surrounds the red central area. A wheal takes about 15-20 minutes to reach its full size, and then fades over a few hours.
A reaction is considered to be 'negative' when the skin remains normal. This means that you are not allergic to the substance in the solution.
Blood test
You may also have a blood test. This measures the amount of a protein called IgE antibody which is produced as a result of an allergic reaction.
Food challenge
If other tests are not conclusive then your doctor may ask you to take part in a food challenge. For this test you are given foods to eat that may or may not contain nuts. You will then be watched closely for 15-30 minutes to see whether you have a reaction. Food challenges are always done at a hospital or specialised setting because of the risk of a severe reaction.
If you are found to be allergic to one type of nut, you may be tested for allergy to other nuts as well. If you have an allergy to peanuts, you are more likely to have an allergy to tree nuts than a person who does not have a peanut allergy. Once an allergy has been confirmed, an allergy specialist will usually help you to devise a plan to manage it. This plan will be individual to you and will take into account how severe your reaction is.
Source: Patient Info