I, like some of the others that responded, found that my son's issues came from our cleaning agents. I would have never known!
I am not going to try to 'sell' you anything, I just want to share my story.
My son was barely a year old. He had a small cough. We went to Hawaii. He came back with pneumonia. That was in August. By Dec. he still had a cough. In January the Dr. was reluctant to diagnose him with asthma, but threw out the words, "Reactive Airway Disease." She sent me home with a breathing machine, loads of steroids, etc. etc. Me being the worry wart that I am, I read all of the information before giving it to my son. I was scared to death to give it to him. I gave him one treatment, maybe two, before I totally flipped and decided I was not going to give these drugs to my baby.
I found a new doctor. I stopped using Lysol in the air, in the trashcans, etc. I stopped sprinkling that yummy smelling carpet powder on our floor. I stopped using Lysol products all together. I clean my floor with vinegar and water. I use as close to natural products I can. Guess what? My son never had a problem again. He does have a bark like cough when he does get sick, but he hardly even gets sick. I knew that these drugs might do more damage to my son than good and I just knew that I couldn't do that.
I urge you to look at your home before doing allergy testing. Unplug any smelly things in your outlets. Purify your home. Put wood floor in her room. You might be surprised. If she goes to preschool, look at that environment as well. Grandma and Grandpa's was a culprit of ours, too.