There are 3 main forms of skin allergy testing; one of which should only be done by a medical professional. Two options are safe to do at home when you are testing for possible allergens to things you already include in your diet.
When performing any of these tests, first clean the area where you intend to conduct the test. A cotton swab and rubbing alcohol will be quite effective.
DIY SKIN PATCH ALLERGY TEST
The patch test takes the longest and may be the least accurate. It involves putting a food item on a patch and putting it on your skin for half an hour up to half a day. If irritation occurs prior to 1/2 hour, by all means, end the test!
The food might have to be broken down and turned into a mush to effectively use it for testing. Just be sure to not contaminate it in the process. Powders can be turned into a paste by adding a few drops of water.
You may want to have a “control” patch to compare to. If you were using a bandage and applying the potential food allergen to the gauze of the bandage, running a comparison with a plain bandage will help you compare results in the event that the test is positive. It will help you realize that the positive result is not from the bandage itself.
A positive test is a red irritation of the skin once the bandage is removed and the allergen rinsed away.
DIY SCRATCH TEST
In a clinical setting, a physician would clean your skin with rubbing alcohol and on separate testing sites add a drop of saline to one location, histamine to a second location, and the potential allergen to another area. The doctor would then irritate the location with a minor scratch or prick with a new sterile medical instrument for each location.
The salt water is merely a control and should not show a reaction. The histamine should be positive for everyone. The allergen should be somewhere between the saline and the histamine. A positive test looks similar to the irritation following a mosquito bite and may be a minor reddening or a little red itchy bump on the skin.
A similar test can be done at home. Clean the skin to be tested. The inside of the forearm or wrist will work well for this. Next, lightly scratch the area to be tested with a clean dull instrument such as a non-serrated butter knife. The skin should not be broken and should definitely not cause bleeding. You shouldn’t even see any skin flakes removed. The gentle scratch is merely to mildly irritate the skin and get the immune systems attention. A nearby control scratch can also be done to have a site of comparison.
Next put a tiny amount of the food mush or paste to be tested directly on one of the scratch locations. Leave it on the skin for 15 to 20 minutes and then rinse it away and compare the scratch marks.
A positive test is an irritation beyond what is seen on the control scratch. If the food causes an irritation, it is probably best to avoid this food in your diet. If the food reacts on your skin, it is certainly reacting in your guts contributing to your inflammatory bowel condition and possible auto-immune disorders.
If you try this DIY test and experience Anaphylaxis, seek medical attention immediately
SKIN INJECTION TEST
The injection test is similar to the skin prick test, but instead of merely scratching or pricking the skin, the allergen is injected shallow under the surface of the skin. This method gives the quickest results, however, it is only to be done by a licensed medical professional.