The symptoms of an allergic reaction occur once the immune system overly reacts to an allergen which is usually harmless such as dust mites, pollen, mold, food or insect stings. If an individual has an allergy, the immune system reacts as if the allergen is a threat, triggering the release of the chemical called histamine that triggers the allergy symptoms.
In case an allergen is something that is breathed in from the air, the reaction will surely affect the nose, eyes and lungs. In case it is something that was eaten, it can affect the mouth, stomach and even the intestines. Remember that a food allergy can trigger skin rashes or asthma-like symptoms. The allergy symptoms tend to vary depending on the type of allergen the individual was exposed to.
Common types of allergy tests
Skin prick test
A skin prick test is commonly used and painless. A minimal amount of the suspected allergen is applied on the skin by creating a small indentation or “prick” on the surface of the arms using plastic pricks.
This type of testing is used to test for food, environmental or spice allergies. If an individual has an allergy, a small-sized red bump similar to a mosquito bite will manifest on the skin. Remember that a positive reaction typically occurs within 20-30 minutes, thus allowing the individual to see what he/she is allergic to during the test. The small-sized hives will vanish within 30 minutes. After the testing, creams and ice can be applied locally to minimize the itchiness and redness in the test site.
Skin patch tests
The patch tests are used for skin allergies or contact dermatitis. This testing can determine if contact with certain chemicals, fragrances, metals or other substances can trigger a rash. The allergens are applied to a patch that is labelled and applied on the back.
The patch test takes a longer time to yield results. The individual will return to the clinic after 48-72 hours to have the patches removed and analyze the testing.
In case the skin prick test result is negative but the doctor still suspects that the individual might have allergies, the intradermal test is used in which a small amount of the allergen is injected within the skin.
Take note that this type of testing is also used confirm the allergy and determine the sensitivity in order to create a serum in case the individual will undergo immunotherapy.
A small amount of the allergen is taken orally or inhaled. The challenges are mostly done with possible food allergies. The challenge tests are always carried out in the clinic under the supervision of a doctor.
The blood tests are typically used when skin testing is not safe or will not suitable for those who are taking medications or have a skin condition that can disrupt with the testing. The blood testing is performed in the clinic and the sample is taken to the laboratory for analysis.