How the Test is Done to Detect Allergies

The allergy test, also called the Prick test or skin allergy test, is used to find out if a person has a skin allergy or not, such as a deodorant , some foods, medications or even if they have a respiratory allergy.

Generally, the allergy test is performed in an allergist or dermatologist's office, and is requested when a person has itchy, swollen or reddened skin. These tests can also be done through blood tests, which determine which substances in the food or environment are most at risk of producing an allergy.

How it is Performed

To perform the allergy test, you should consult an allergist or dermatologist, who, depending on the type of allergy, will recommend one of the following skin allergy tests:

• Allergy test on the forearm : a drop is dropped on the forearm, some of them with substances that could probably cause allergy, or you can also get a picket with a needle that contains the substance, wait about 20 minutes to check if the patient reacts;
• Allergy test on the back: also known as contact allergy test, it consists of sticking an adhesive cloth on the patient's back with a small amount of substance that is thought to cause allergy to the patient, then wait up to 48 hours and observe if any skin reaction arises.

Skin allergy tests can be performed to detect an allergy in anyone, including babies, and the positive reaction consists of a red blister formation, resembling a mosquito bite, which leads to inflammation and itching of the area.


In addition to these tests, the patient may be asked for a blood test to assess whether there are substances in the blood that indicate if the individual has any type of allergy.

In the case of allergy to food, such as milk, gluten or shrimp, for example, the doctor may recommend conducting a food exposure test, which consists of eating a small amount of food that could cause allergy and Check if it causes a reaction.

How to Prepare for the Allergy Test 

The preparation for the allergy test should include:

• Eliminate the use of antihistamines , such as Hydroxizine or Sensibit, for example, two weeks before performing any allergy test, as it may interfere with the results, preventing the reaction to the substance to which you are allergic;
• Avoid applying creams on the skin , as it may lead to an incorrect result when the Prick test is performed.

In addition to these points, the patient must comply with all the specific indications that the doctor gave him, so that the test can correctly report the results.