To evaluate the changes in proinflammatory markers (ltd4 in urine) and eosinophil from peripheral blood after newly initiated montelukast therapy.

Inclusion Criteria:

• Allergic rhinitis symptoms: sneezing, rhinorrhea, obstruction of the nasal passages, itchy nose and throat, and conjunctival
• Male or female outpatient 20 years of age and older
• Patients with the following signs and symptoms of asthma and allergic rhinitis: history of cough, wheezing, shortness of breath, positive methacholine bronchoprovocation test

Exclusion Criteria:

• Active, acute or chronic, pulmonary disorder (besides asthma) documented by history, physical examination, or chest x-ray. history of anaphylactic or hypersensitive to study drug
• Requires oral, intravenous, or intramuscular corticosteroids on daily routine basis
• Started on immunotherapy within six months before the pre-study visit and/or the dose of immunotherapy is expected to change over the course of the study
• Treated with montelukast within 3 months before enrollment
• Unable to perform acceptable, reproducible spirometry and peak flow measurement
• Unresolved symptoms and signs of an upper respiratory tract infection (uri) within 2 weeks prior to visit 1