The purpose of this study is to investigate whether buffered hypertonic saline (BHS) is superior to normal saline (NSS) for improving mucociliary function and relief nasal symptoms in children with allergic rhinitis.

1. BHS is superior to NSS for improving mucociliary function that by measure saccharine clearance time(SCT)at 10 minute after nasal irrigation compare to baseline.

2. BHS is superior to NSS for clinical effectiveness at short period and 1 month follow up

   • at short period: compare the following results at baseline and 10 minute after nasal irrigation

     1. total nasal symptom score(TNSS)
     2. satisfaction to nasal irrigation
     3. side effect

   • at 2 and 4 weeks follow up : compare the following results at baseline and 10 minute after nasal irrigation

     1. quality of life(by specific questionnaire for Thai allergic rhinoconjunctivitis patient)
     2. medication use to relieve AR symptom(from diary record)
     3. compliance for nasal irrigation (from diary record)
     4. side effect (from diary record)
     5. overall satisfaction to nasal irrigation

Inclusion Criteria:

1. age 6-15 years
2. diagnosed AR obtained by history, physical examination and positive skin prick test or nasal cytology
3. TNSS ≥ 4 at the first visit of this study

Exclusion Criteria:

1. Patients with a history of nasal anatomical defects
2. Abnormal nasal ciliary function or an upper respiratory tract infection in the preceding 2 weeks