WHAT'S KNOWN ON THIS SUBJECT: Primary ciliary dyskinesia presents in infancy with unexplained neonatal respiratory distress, yet diagnosis is often delayed until late childhood. Earlier diagnosis facilitates earlier onset of therapy, which may help to reduce long-term pulmonary morbidity and mortality. WHAT THIS STUDY ADDS:A diagnostic workup for primary ciliary dyskinesia should be considered in a term infant presenting with unexplained respiratory distress and either lobar collapse, situs inversus, or a prolonged oxygen therapy requirement (.2 days). abstract BACKGROUND AND OBJECTIVE: Primary ciliary dyskinesia (PCD) is a rare inherited disease affecting motile cilia lining the respiratory tract. Despite neonatal respiratory distress as an early feature, diagnosis is typically delayed until late childhood. Our objective was to identify characteristics that differentiate PCD from common causes of term neonatal respiratory distress. METHODS:This was a case-control study. Patients with PCD born after 1994 attending a regional PCD clinic who had a history of neonatal respiratory distress (n = 46) were included. Controls (n = 46), term neonates with respiratory distress requiring a chest radiograph, were randomly selected from hospital birth records and matched on gender, birth month/year, and mode of delivery. Multiple logistic regression was used to determine the association between neonatal characteristics and PCD diagnosis. The diagnostic performance of the best predictive variables was estimated by calculating sensitivity and specificity.RESULTS: PCD cases required more oxygen therapy (39 cases, 29 controls, P = .01), longer duration of oxygen therapy (PCD mean = 15.2 days, control mean = 0.80 days, P , .01), had later onset of neonatal respiratory distress (PCD median = 12 hours, control median = 1 hour, P , .001), and higher frequency of lobar collapse and situs inversus (PCD = 70% and 48% respectively, control = 0% for both, P , .001). Situs inversus, lobar collapse, or oxygen need for .2 days had 87% (95% confidence interval: 74-94) sensitivity and 96% (95% confidence interval: 85-99) specificity for PCD. CONCLUSIONS:When encountering term neonates with unexplained respiratory distress, clinicians should consider PCD in those with lobar collapse, situs inversus, and/or prolonged oxygen therapy (.2 days).

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Background: Asthma exacerbation trajectories in children after incident asthma diagnosis are understudied. Objective: To identify trajectories of asthma exacerbation and predictors of these trajectories in children with incident asthma. Methods: Children from the National Longitudinal Survey of Children and Youth, Canada, with incident asthma were followed-up for up to 12 years during childhood. Latent class growth modeling was used to identify distinct asthma exacerbation trajectory groups. Multinomial logistic regression was performed to identify predictors of trajectory group membership. Results: The mean age at asthma diagnosis among 403 children was 5.9 years. Three distinct trajectories were identified: low increasing (21.3% of children), medium decreasing (45.8% of children), and high decreasing (32.8% of children). Asthma attack probability increased gradually after diagnosis in low increasing group, decreased from moderate level after diagnosis to almost zero probability at the end of follow-up in the medium decreasing group, and decreased after diagnosis but remained higher in the high decreasing group than the other 2 groups at 12 years after diagnosis. Children having more siblings at home were more likely to belong to the medium decreasing and high decreasing trajectory groups, whereas children older at asthma diagnosis were less likely to belong to the medium decreasing and high decreasing trajectory groups than the low increasing trajectory group. Conclusion: Our results suggest that children with incident asthma follow 3 distinct trajectories of asthma exacerbations after asthma diagnosis. The trajectory group with initial moderate exacerbation probability has better long-term prognosis.

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