Suggest Treatment For Chronic Cough With Wheezing

My daughter had a viral upper respiratory tract infection about 6 months ago and since that has had a chronic cough, worse at nights, sometimes associated with wheezing, and certainly worsened by milk products/chocolates. She has hada chest x-ray, blodd tests etc, and has been diagnosed with asthma. However, on good doses of inhaled fluticasone/oral monteleukast/ zyrtec and albuterol prn, she has not improved much. Some doctors say this is astma, others say she has allergies. She sometimes coughs so much at night that she vomits. SHe has also been prescribed a few rounds of antibiotics (azithromycin, cefuroxime) without help. She does snore at night, and does have eczema. Since the astma meds were not helping much we have stopped them, but she continues to have a cough most days. There is no fever. She usually ahs a good appetite. need help!