The skin sensitivity test can indicate two different things. In the first case it is a medical procedure, the patch test, useful for diagnosing some contact allergies. In the second case, reference is made to a "home" examination to see if you can spread the new product you have purchased. In both cases, however, an allergic reaction to an irritant is sought.
Steps
Method 1 of 2: Undergo a Skin Allergy Test
Step 1. Learn the basic principles
The patch test is used to quantify the allergic response of the skin to contact with particular substances. This is a different exam from the prick test.
- Through the prick test we look for reactions to common allergens that cause symptoms such as hives or rhinorrhea. A nurse scratches or pricks the skin to get the potentially irritating substance under the epidermis.
- The patch test instead reveals the reaction of the skin to the allergen. This reaction is called contact dermatitis.
Step 2. Review medications with your doctor
Some active ingredients can alter the result of the patch test. Antihistamines, for example, are designed to suppress the allergic reaction by actually modifying the results of the test. Your doctor may ask you to stop taking therapy for some time before you get tested, up to 10 days before the test.
Other medicines that may interact negatively are tricyclic antidepressants, some acid reflux medicines (such as ranitidine) and omalizumab (an asthma medicine)
Step 3. Be prepared for what will happen
During the examination, a nurse or doctor himself prepares a series of small patches, each containing a small amount of a different substance known to trigger allergic reactions in some individuals. For example, in some cases everything is used, from metals such as cobalt and nickel to lanolin and certain plant substances. The patches are applied directly to the back with medical adhesive tape. Typically, the site of choice is the back or the arm.
Step 4. Ask for a photopach test
If you often suffer from rashes on the back of your hands, neck or arms, your skin may react negatively to substances only when exposed to sunlight. There is a special examination to diagnose this problem; if you need a photopach test, the doctor puts a couple of each substance in contact with the epidermis, exposing only one to light while the other remains covered.
Step 5. Don't be afraid to feel pain
Unlike the prick test, this test does not involve the use of needles; as a result, you feel no pain when the patches are applied.
Step 6. Keep the area dry
While keeping the patches in contact with your skin, you should avoid getting them wet - this means you shouldn't sweat excessively or expose yourself to high humidity. Don't swim, don't shower, don't bathe, don't exercise, and don't do any activity that could get the patches wet.
Step 7. Wait two days
The patches should typically be left in place for two days; after this time you must go back to the doctor. The nurse or allergist removes the patches and looks at the skin to see which substance triggered a skin reaction.
The skin may experience rashes that appear as small raised bumps or fluid-filled sacs
Step 8. Wait another couple of days
Sometimes, the doctor wants to see you again, after four days of applying the substances, so that he can observe the late reactions to the allergen.
Step 9. Avoid irritants
When you know the substances that are bothering you, you know what to avoid. Your doctor may advise you not to touch a particular item. Otherwise, if you do not experience any reactions, your doctor will perform further tests to determine the causes of the rashes you are suffering from.
Method 2 of 2: Testing New Products on the Skin
Step 1. Understand the procedure
When buying a new product, such as a chemical peel or even a simple facial cleanser, it is important to have a skin sensitivity test, especially if you have sensitive skin. In this case, you need to apply a small amount of the cosmetic on a small area of the epidermis to observe the reactions.
- In other words, you shouldn't smear a substance all over your face or body that could trigger widespread hives; at the beginning it is better to circumscribe the surface.
- You should also test other products in the same way, such as shampoo, conditioner, and hair dyes. Basically, if you have delicate skin, you should test any cosmetic or substance you plan to use.
Step 2. Apply a small amount to the inside of the arm
This area is perfect for testing, as it is covered with sensitive skin. Furthermore, the eventual reaction will not be too visible to other people.
If you feel stinging or notice an immediate negative response, wash off the product as quickly as possible
Step 3. Wait 24 hours
If you are testing a lotion, leave it on the skin. If it is a substance, such as a chemical peel that needs to be rinsed off, remove it after the time indicated on the package has elapsed. Wait an internal day to see if there are any skin reactions.
If it is, the skin becomes red, swollen or shows a real rash. It may peel or ooze liquid; another symptom is itching
Step 4. Repeat the test on an even more sensitive area
Next, you need to try the product on an area of the body where the skin is more delicate. For example, if you are testing a facial cleanser, apply a small amount behind the ear. The reason for this second test is that the ingredients could inflame a more delicate area, but not the inside of the arm.
Step 5. Wait another day
You have to be patient one day inside again, looking for any skin reactions to the substance. If you do not notice any alterations, you can use the product with peace of mind.
Advice
- The first type of test can help you understand which products you can use for skin care; when you know the substances that irritate the skin, you can check that they are not present in the ingredients list of cosmetics.
- The second test is suitable for a wide variety of products, including perfumes, makeup, shampoos, deodorants, aftershaves, sunscreens, hair removal creams, and other cosmetics that you apply directly to the skin.
