Hi, G.!
I haven't had my younger son tested *yet*, but I was tested at a very early age, and we are planning on having him tested soon, too. The procedure is done by 1 of 2 ways now: the first way is to do a "skin patch" test, where they will "prick" your daughter's back with specific allergens. Each area that develops a "whelp" on her back is a positive reaction to that allergen. The whelps are graded on a scale of 1 to 4, with 4 being a severe allergy. Yes, it will itch and it will be a little, and I mean just a little, painful as they "prick" her skin. I would ask the dr if it's ok to give her some Tylenol prior to the test, but I would not give it to her without the dr's approval. The 2nd way is to simply draw some blood, and run it through the lab to see if there are any antigens to the allergens being introduced. I know adults can have their allergies tested this way now, but I'm not sure if they are testing children this way or not, yet.
It's my personal opinion that it is best to go ahead and get her tested. That way you will know what she is allergic to, and you can start helping her avoid it (foods and dust), or treat it with the appropriate meds (pollens and other environment, plus the foods/dust). If you don't, she will just *suffer*, and that's not a good thing, especially if the allergies turn out to be severe. Your pedi should be able to recommend an allergist to test and treat your daughter. Just remember to call the dr and verify that they take your insurance first. If you have any more questions, feel free to email me at ____@____.com, or you can call me at ###-###-####. I'm a sahm.
Hope your daughter starts feeling better! ~J.~