I had allergy scratch tests done less than a year ago. They ask you many questions about what things bother you and what you think you may be allergic to or want to be checked for. They do a medical history. They make a grid map on your back, then the rub your back with this alcohol like substance and then make pricks in you back sticking the needles in. Now, I hate needles and was terrified to have it done but it doesn't hurt at all. Just feels a little funny. They leave them in for about 10 minutes and then come back to see. If where the are any red raised bumps or a rash of some sort then you are most likely allergic to that which you were tested for. If you are the area where the needle is usually becomes red and swollen and itchy. It was really a simple test however it is not guarrentee. There are many things that did not show up in a blood test but showed up on the scratch test, and vice versa. Some things just show up but you are allergic to them. So there is nothing that is 100% accurate at catches everything that you are allergic to. I hope that helps you someone. If you have any more questions ask, and I will do the best I can to answer them for you! Let me know how things go!