Skin Patch Test - Patch Testing for Skin Allergies
What is Skin Patch Testing?
Patch testing is a way of figuring out whether a chemical or organic substance that comes in contact with your skin is causing contact dermatitis or in layman's terms: inflammation of the skin. There are two types of contact dermatitis: irritant contact dermatitis and allergic contact dermatitis.
What is irritant contact dermatitis?
An chemical or organic irritant is a substance that would cause inflammation in almost every individual if it was applied in concentration for a long enough time. Reaction irritation is caused by the direct contact of one of these substances with the skin and does not involve the immune system. It is rather a topical issue.
What is allergic contact dermatitis?
An allergic reaction is going to be individual by person and substances which are called allergens. An allergy is a hypersensitivity or over sensitivity to a particular chemical or compound. This reaction involves the immune system. A rash will develop in the areas of skin that were in contact with the allergenic substance.
How does skin patch testing help?
Skin testing can help to understand which reaction you may have to an essential oil. You may find that your solution is too concentrated and it irritates your skin, or you might find that you are actually allergic to a certain organic compound and must strive to stay away from it, not only on your skin, but in vapors that you inhale also.
How to Skin Patch Test
The test involves the application of one essential oil to the skin under adhesive tape and left in place for 48 hours. The skin is then examined a further 48 hours later for any response.
Leave the patch in place for 48 hours. After 48 hours remove the patch and wait one hour.
Take your first reading after that first hour wait.
The final reading is taken another 48 hours later.
Cautions - Do not wash the area or play sports or participate in any activity that is vigorous or causes you to sweat, because if the adhesive tape peels off, you will have to repeat the process.
Refrain from bathing or washing until the last reading is taken. Furthermore, the patches should not be exposed to sunlight or other sources of ultraviolet (UV) light.
Reading the Results
Score your reaction, if any, as follows:
- doubtful reaction: mild redness only.
- weak, positive reaction: red and slightly thickened skin.
- strong positive reaction: red, swollen skin with individual small water blisters.
- extreme positive reaction: intense redness and swelling with coalesced large blisters or spreading reaction.
- irritant reaction. Red skin improves once patch is removed.
The distinction between allergic and irritant reactions is very important. An irritant reaction shows up immediately after the patch is removed and fades over the next 24 hours. If you are having an actual allergic reaction it will take a few days to develop, and will be more prominent in five days than when the patch is first removed.
If you find that you have had an allergic reaction to an essential oil or a carrier oil, the substance should be avoided altogether, as the more times your skin is exposed to the compound, the worse your allergic reaction will be.
