Nasal provocation
a) Patient will challenge by the allergen solvent first as solvent control. A special nasal spray device will be used for nasal provocation tests. Two doses will be sprayed on each side of the nasal cavity, with an average of 0.05 mL each dose, one in the direction of the common nasal meatus, and the other in the direction of the middle meatus. Patient should to take a deep breath before spraying, then hold breath during the spraying procedure, take deep breath afterwards. Then we will evaluate the symptom and nasal examination within 10 minutes in chronological order. We found the solvent provocation did not cause more than 50% of the symptoms increased or 30% nasal flow decreased. (Table E2). So the allergen solvent challenge is negative, we can do allergen solution provocation.
b) The nasal allergen provocation was performed at least 10 mins after solvent control. Same as solvent provocation, two doses spray will be given on each side of patient’s nasal cavity, with an average of 0.05 mL each dose, one in the direction of the common nasal meatus, and the other in the direction of the middle meatus. Patient should to take a deep breath before spraying, then hold breath during the spraying procedure, take deep breath afterwards. Then we will evaluate the symptom and nasal examination within 10 minutes in chronological order. The provocation is defined as positive when subjective measures is clearly positive or objective measures is clearly positive or both subjective and objective measures are moderately positive, based on the EAACI Position paper on the standardization of nasal allergen challenges. After allergen challenge, the symptom score increased by more than 50% and the nasal airflow decreased by more than 30% compared with baseline and solvent control. The nasal provocation test was successful (Table E2).