Definitions of outcomes
Allergic rhinitis was diagnosed by a pediatric allergy specialist
using the following criteria: (1) Current upper respiratory symptoms
(nasal blockage, rhinorrhea, nasal itching and sneezing after allergen
exposure); (2) At least one positive SPT to common inhalant allergens.
The symptoms were classified as “seasonal” when they were
limited to a certain period or a season, and as “perennial“when they occurred throughout the year. Duration of the symptoms was
classified according to ARIA guidelines(6) as “Intermittent ”
(the symptoms present less than 4 days a week or for less than 4
consecutive weeks) or “Persistent ” (present more than 4 days a
week and for more than 4 consecutive weeks). AR was classified as
“mild ” when none of the severity items (sleep disturbance,
impairment of daily activities, leisure and/or sport, impairment of
school or work and presence of troublesome symptoms) was present, and as
“moderate/severe ” in patients with one or more of the
aforementioned items.
Allergic conjunctivitis: Defined as the presence of current
ocular symptoms (tearing, burning, itching and redness in the eyes) and
positive SPT.
Physician-diagnosed asthma: Defined as current symptoms (wheeze
and cough) and positive bronchodilator responsiveness (improvement of
FEV1 by 12% or more following administration of 200 mcg
salbutamol), and/or a positive response to a trial of therapy with
inhaled or oral corticosteroids(19).
Atopic dermatitis: Current pruritus and a relapsing eczematous
rash typically found over flexor surfaces.
Allergic sensitization: SPT mean wheal diameter at least 3 mm
greater compared to the negative control.
Parental asthma and parental allergic rhinitis were
determined by questionnaire at enrollment.