Reference values for respiratory sinusoidal oscillometry in children aged 3 to 17 years.

BACKGROUND: New oscillometry devices allowing quantification of respiratory function using tidal breathing are commercially available, but reference equations are lacking for the multiethnic Canadian pediatric population. METHODS: We conducted a prospective cross-sectional study of healthy children carefully selected for absence of asthma, atopy, tobacco smoke, obesity, prematurity, and recent respiratory infection. Triplicate measures were obtained of respiratory system resistance (Rrs) and reactance (Xrs), area under the reactance curve (AX) and resonant frequency (Fres) on four signals, whose testing order was randomized: two signals on the Resmon Pro Full (8 Hz and 5-11-19 Hz) and two signals on the tremoflo C-100 (5-37 Hz and 7-41 Hz). Feasibility was defined as the ability to obtain valid reproducible results. Prediction equations and 95% confidence intervals were derived for whole- and within-breath Rrs and Xrs and for AX and Fres, using linear regression or Generalized Additive Models for Location, Scale and Shape. RESULTS: Of 306 children randomized, valid and reproducible results on ≥1 signal were obtained in 299 (98%) multiethnic (69% Caucasians: 8% Black: 23% Others) children aged 3-17 years, 91-189 cm tall. Standing height was the strongest predictor with no significant effect of sex, age, body mass index or ethnicity. Significant within-patient differences were observed between Resmon Pro and tremoflo C-100 measurements, justifying the derivation of device-specific reference equations. CONCLUSION: Valid reproducible oscillometry measurements are highly feasible in children aged 3 years and older. Device-specific reference equations, valid for our multiethnic population, are derived.

Cold urticaria in a pediatric cohort: Clinical characteristics, management, and natural history.

BACKGROUND: Cold urticaria (coldU) is associated with substantial morbidity and risk of fatality. Data on coldU in children are sparse. We aimed to evaluate the clinical characteristics, management, risk of associated anaphylaxis, and resolution rate of coldU in a pediatric cohort. Additionally, we sought to compare these metrics to children with chronic spontaneous urticaria (CSU). METHODS: We prospectively enrolled children with coldU from 2013-2021 in a cohort study at the Montreal Children's Hospital and an affiliated allergy clinic. Data for comparison with participants with solely CSU were extracted from a previous study. Data on demographics, comorbidities, severity of presentation, management, and laboratory values were collected at study entry. Patients were contacted yearly to assess for resolution. RESULTS: Fifty-two children with cold urticaria were recruited, 51.9% were female and the median age of symptom onset was 9.5 years. Most patients were managed with second-generation H1-antihistamines (sgAHs). Well-controlled disease on sgAHs was negatively associated with concomitant CSU (adjusted odds ratio (aOR) = 0.69 [95%CI: 0.53, 0.92]). Elevated eosinophils were associated with cold-induced anaphylaxis (coldA; aOR = 1.38 [95%CI: 1.04, 1.83]), which occurred in 17.3% of patients. The resolution rate of coldU was 4.8 per 100 patient-years, which was lower than that of CSU (adjusted hazard ratio = 0.43 [95%CI: 0.21, 0.89], p < 10-2 ). CONCLUSION: Pediatric coldU bears a substantial risk of anaphylaxis and a low-resolution rate. Absolute eosinophil count and co-existing CSU may be useful predictive factors.

Physician's perspective regarding asthma guided self-management: directives or guidance?

INTRODUCTION: Asthma guided self-management enhances patients' control of their condition under the guidance of the treating physician. The aim of the present study was to understand how physicians perceive, endorse, uptake, and support asthma guided self-management. METHODS: We conducted a secondary supplementary analysis of data originally collected as part of a multicenter collective case study in which physicians treating patients with asthma were interviewed. Using reflective thematic analysis, we aimed to explore physicians' understanding of guided asthma self-management as related to four ideas, namely: (a) understanding of the disease management and treatment goals; (b) defining medical frame and guidance; (c) describing the importance of patient-physician relationship; and (d) implementing asthma guided self-management. RESULTS: Evidence indicates that physicians perceived optimal guided self-management as related to patients' adherence to physician's instructions and recommendations, supported by the adjustment of prescribed pharmaceutical therapy contingent upon patient's symptoms. Some physicians also perceived behavior change and environmental control along with the medical recommendations. While physicians' perception of asthma and its treatment were aligned with the recommended guidelines-i.e., patient-centered care approach based on guided self-management, the actual guidance offered to patients remained primarily directive and paternalistic. Non-pharmacological approaches, such as exercise, smoking cessation, patient self-monitoring, and self-management supported by education and written self-management plans, were given little consideration in the context of the recommended treatment plan.

Clinical Characteristics, Management, and Natural History of Chronic Inducible Urticaria in a Pediatric Cohort.

BACKGROUND: Some forms of chronic urticaria (CU) can be specifically attributed to a response to a definite trigger, referred to as chronic inducible urticaria (CIndU). We aimed to assess the demographics, clinical characteristics, comorbidities, natural history, and management of pediatric patients with CIndU. METHODS: Over a 6-year period, children presenting to the allergy clinic at the Montreal Children's Hospital (MCH) with CIndU were prospectively recruited. CU was defined as the presence of wheals and/or angioedema, occurring for at least 6 weeks. A standardized diagnostic test was used to establish the presence of a specific form of urticaria. Resolution was defined as the absence of hives for 1 year without treatment. RESULTS: Sixty-four patients presented with CIndU, of which 51.6% were male, with a median age of 12.5 (interquartile range 7.3, 15.9) years. Cold CU and cholinergic CU were the most common subtypes (60.3 and 41.3%, respectively). Basophil counts were undetectable in 48.4% of the cases, and C-reactive protein levels were elevated in 7.8% of patients. Of all cases, 71.4% were controlled with second-generation antihistamines. The resolution rate was of 45.3% (95% confidence interval 33.1-57.5%), based on per-protocol population within the 6-year course of the study. Resolution was more likely in patients who presented with well-controlled urticaria control test scores and elevated CD63 counts and in those suffering from thyroid comorbidity. CONCLUSION: The natural history of CIndU resolution in pediatric patients was relatively low and was associated with elevated CD63 levels, as well as thyroid comorbidity.

Community Use of Epinephrine for the Treatment of Anaphylaxis: A Review and Meta-Analysis.

BACKGROUND: Community use of epinephrine for the treatment of anaphylaxis is low. Knowledge of rates of epinephrine use in the pre-hospital setting along with identification of barriers to its use will contribute to the development of policies and guidelines. OBJECTIVES: A search was conducted on PubMed and Embase in April 2020. Our systematic review focused on 4 domains: (1) epinephrine use in the pre-hospital setting; (2) barriers to epinephrine use in the pre-hospital setting; (3) cost evaluation and cost-effectiveness of epinephrine use; and (4) programs and strategies to improve epinephrine use during anaphylaxis. METHODS: Two meta-analyses with logit transformation were conducted to: (1) calculate the pooled estimate of the rate of epinephrine use in the pre-hospital setting among cases of anaphylaxis and (2) calculate the pooled estimate of the rate of biphasic reactions among all cases of anaphylaxis. RESULTS: Epinephrine use in the pre-hospital setting was significantly higher for children compared with adults (20.98% [95% confidence interval (CI): 16.38%, 26.46%] vs 7.17% [95% CI: 2.71%, 17.63%], respectively, P = .0027). The pooled estimate of biphasic reactions among all anaphylaxis cases was 3.92% (95% CI: 2.88%, 5.32%). Our main findings indicate that pre-hospital use of epinephrine in anaphylaxis remains suboptimal. Major barriers to the use of epinephrine were identified as low prescription rates of epinephrine autoinjectors and lack of stock epinephrine in schools, which was determined to be cost-effective. Finally, in reviewing programs and strategies, numerous studies have engineered effective methods to promote adequate and timely use of epinephrine. CONCLUSION: The main findings of our study demonstrated that across the globe, prompt epinephrine use in cases of anaphylaxis remains suboptimal. For practical recommendations, we would suggest considering stock epinephrine in schools and food courts to increase the use of epinephrine in the community. We recommend use of pamphlets in public areas (ie, malls, food courts, etc.) to assist in recognizing anaphylaxis and after that with prompt epinephrine administration, to avoid the rare risk of fatality in anaphylaxis cases.