Introduction: Lung function testing in pre-school children in the clinical setting is

Background Management of preschool wheeze is based predominantly on symptom patterns. Objective To determine whether personalizing therapy using blood eosinophils or airway bacterial infection results in fewer attacks compared with standard care. Methods A proof‐of‐concept, randomized trial to investigate whether the prescription of inhaled corticosteroids (ICS) guided by blood eosinophils, or targeted antibiotics for airway bacterial infection, results in fewer unscheduled healthcare visits (UHCVs) compared with standard care. Children aged 1–5 years with ≥2 wheeze attacks in the previous year were categorized as episodic viral wheeze (EVW) or multiple trigger wheeze (MTW). The intervention group was prescribed ICS if blood eosinophils ≥3%, or targeted antibiotics if there is positive culture on induced sputum/cough swab. The control group received standard care. The primary outcome was UHCV at 4 months. Results 60 children, with a median age of 36.5 (range 14–61) months, were randomized. Median blood eosinophils were 5.2 (range 0–21)%, 27 of 60 (45%) children were atopic, and 8 of 60 (13%) had airway bacterial infection. There was no relationship between EVW, MTW and either blood eosinophils, atopic status or infection. 67% in each group were prescribed ICS. 15 of 30 control subjects and 16 of 30 patients in the intervention group had UHCV over 4 months (p = .8). The time to first UHCV was similar. 50% returned adherence monitors; in those, median ICS adherence was 67%. There were no differences in any parameter between those who did and did not have an UHCV. Conclusion Clinical phenotype was unrelated to allergen sensitization or blood eosinophils. ICS treatment determined by blood eosinophils did not impact UHCV, but ICS adherence was poor.

Little is known about adherence to inhaled corticosteroids (ICS) in preschool children with troublesome wheeze. Children with aeroallergen senitization, or those reporting multiple trigger wheeze (MTW), are more likely to respond to ICS. We hypothesized that adherence to ICS and symptom control are only positively related in atopic children, or those reporting MTW. Patients aged 1 to 5 years with recurrent wheeze prescribed ICS were recruited from a tertiary respiratory clinic. Clinical phenotype and aeroallergen senitization were determined, and adherence assessed using an electronic monitoring device (Smartinhaler). Symptom control (test for respiratory and asthma control in kids [TRACK]), quality of life (PACQLQ), airway inflammation (offline exhaled nitric oxide) were assessed at baseline and follow‐up. Forty‐eight children (mean age 3.7 years; SD, 1.2) were monitored for a median of 112 (interquartile range [IQR], 91‐126) days. At baseline n = 29 reported episodic viral wheeze and n = 19 reported MTW. Twenty‐four out of 48 (50%) wheezers had suboptimal ICS adherence (<80%). Median adherence was 64% (IQR, 38‐84). There was a significant increase in TRACK and PACQLQ in the group as a whole, unrelated to adherence. In subgroup analysis only atopic wheezers with moderate or good adherence ≥ 60% had a significant increase in TRACK. There was no relationship between clinical phenotype, and adherence or TRACK. In this pilot study, overall adherence to ICS was suboptimal and was positively related to symptom control in atopic wheezers only. Assessments of adherence are important in preschool troublesome wheezers before therapy escalation to help identify those with an ICS responsive phenotype.