Nothing is working, so why keep taking meds?

My daughter is 3.5 yrs. old and has battled chronic sinus infections and bronchitis for most of her life.
There is no immune testing she has not under gone, has seen two ENT's, had her adenoids removed, has seen a pulminilogist who did a bronch. on her and said she had AD (allergy, excercise induced asthma), has been to three pediatric allergist, one found nothing, one found a few minor things, and one found multiple things.
She is currently on sublingual therapy for the positive allergy tests. Although her pulminologist ran a SW RAST and a hypersensitivity test and both came back negative.
So I am not sure how one dr. found so many things when the others did not. I have an appoinment with a fourth allergist to pose this question. I will not have her tested again......I think three times in three years is more than a toddler should have to endure. Each time there are blood draws and skin tests.
She takes daily...........allergra, singular, pulmicort, xopenex, previcid, duradryl, nasonex, foradil. Is on antibiotics and steroids every month as well.
She has had bronchitis 7 times in seven months, 4 sinus infections, 2 double earinfection, suffers from post infectious coughs which keeps her on her neb. literally around the clock, every three hours.
This has been our life for the past three years. Obviously all the meds do not help, they barely help relieve her symptoms and certainly they do not prevent her from getting sick.
We have taken the carpeting out of her room, she has 2 HEPA air filters in her room, a dehumidifier, all bedding is encased, sheets and pillows are laundered with a special anti-dust mite laundry aditive, no stuffed animals allowed, no pets in the house, she doesn't go outside for recess at school or nap on the floor. But yet, every three weeks we go through the same thing. After weeks of antibiotics she has about a one week reprieve and then it all starts all over.
Runny nose, cough, infection............boom boom boom. You can set your watch by it. She misses school three weeks a month........last year I took her out of school completely as I did the year before (not really school, but a two day a week mothers day out program) and she continued to get sick staying home with me full time.
I can't imagine all these neds are good for her body. I want to know why I should continue to pump her full of meds that do not control a single symptom.
Anyone have a similar story with a different out come? I am seriously considering pulling her off all the meds.........but that also means she will have to stop the drop therapy, anyone's kid out grow something similar?

Your poor baby! I can kind of relate with you. My son (who is now 14) was constantly sick with ear infections, sinus infections, bronchitis, upper respitory infections etc up until the age of 5. It turned out that he had severe allergies as well as seasonal asthma. These doctors that you take her to, do they specialize in pediatrics? I found that a pediatric specialist is way more helpful then one that you would find for an adult. I can't say if your daughter will outgrow this or not, but if it's any encouragement, my son did. He outgrew his allergies by age 8, his seasonal asthma by 7 and to this day very rarely gets ill anymore.