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In a prospective, multicenter cohort of infants hospitalized with bronchiolitis, we found infants born late pre-term (ie, gestational age of 34-36.9 weeks) had 35% higher odds of having asthma by age 5 years compared with infants born at full-term., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Increasing evidence shows that environmental factors in childhood play a role in development of irreversible airway obstruction. We evaluated early-life and preschool-age risk factors for irreversible airway obstruction in adolescence after bronchiolitis in infancy., Methods: This study is a secondary analysis of data collected during prospective long-term follow-up of our post-bronchiolitis cohort. Risk factor data were collected during hospitalisation and on follow-up visits at 5-7 and 10-13 years of ages. Lung function was measured from 103 participants with impulse oscillometry at 5-7 years of age and from 89 participants with flow-volume spirometry at 10-13 years of age., Results: Asthma diagnosis at <12 months of age showed a significant association with irreversible airway obstruction at 10-13 years of age independently from current asthma. Irreversible airway obstruction was less frequent in children with variant than wild genotype of the Toll-like receptor 4(TLR4) rs4986790, but the significance was lost in logistic regression adjusted for current asthma and weight status. Higher post-bronchodilator respiratory system resistance at 5 Hz and lower baseline and post-bronchodilator reactance at 5 Hz by impulse oscillometry at 5-7 years of age were associated with irreversible airway obstruction at 10-13 years of age., Conclusion: Asthma diagnosis during the first living year and worse lung function at preschool age increased the risk for irreversible airway obstruction at 10-13 years of age after bronchiolitis. TLR4 rs4986790 polymorphism may be protective for development of irreversible airway obstruction after bronchiolitis., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Children with a history of rhinovirus (RV) positive bronchiolitis have a high risk of developing subsequent asthma. Maternal asthma might also increase this risk. The aim of this study was to investigate the combined effects of hospitalization for RV positive bronchiolitis in infancy and a history of maternal asthma on the development of asthma at preschool age., Methods: This is a prospective cohort study of 139 preschool-aged children, with a history of hospital admission for bronchiolitis in infancy, followed-up to ascertain asthma and asthma-like symptoms, skin prick allergy test positivity, and lung function measured pre- and post-bronchodilator using impulse oscillometry., Results: Children with a past hospitalization for RV positive bronchiolitis (42.4% of all) and a history of maternal asthma (36.7% of all) had the greatest prevalence and risk ratio (RR) for doctor-diagnosed asthma (prevalence 81.8% and RR 2.10, 95% confidence interval [CI] 1.37-3.19, p = .001), use of inhaled corticosteroids (68.2% and RR 2.17, 95% CI 1.19-3.99, p = .001) and short-acting β-agonists in the last 12 months (95.2% and RR 1.49, 95% CI 1.17-1.89, p = .001), as compared to those with RV negative bronchiolitis and no maternal asthma history. More children in this group had an abnormal airway resistance (33.3% and adjusted risk ratio [aRR] 3.11, 95% CI 1.03-9.47, p = .045) and reactance (27.8% and aRR 2.11, 95% CI 1.06-4.26, p = .035) at 5 Hz, as compared to those with RV negative bronchiolitis and no maternal asthma history., Conclusion: Hospitalization for RV positive bronchiolitis in early life combined with a history of maternal asthma identifies a subgroup of children with a high asthma burden while participants with only one of the two risk factors had intermediate risk for asthma., (© 2020 Wiley Periodicals LLC.)

Background: The transition from early childhood wheezing to persistent asthma is linked to lung function impairment over time. Little is known how the methods used to study lung function at different ages correlate longitudinally., Methods: Sixty-four children with a history of hospitalization for bronchiolitis before 6 months of age were prospectively studied with impulse oscillometry (IOS) at the mean age of 6.3 years and these preschool IOS results were compared with flow-volume spirometry (FVS) measurements at mean age of 11.4 years., Results: The baseline respiratory system resistance at 5 Hz (Rrs5) showed a modest statistically significant correlation with all baseline FVS parameters except FVC. The post-bronchodilator (post-BD) Rrs5 showed a modest statistically significant correlation with post-BD FEV 1 and FEV 1 /FVC. The bronchodilator-induced decrease in Rrs5 showed a modest statistically significant correlation with the percent increase in FEV 1 . Baseline and post-BD respiratory reactance at 5 Hz (Xrs5) showed a modest statistically significant correlation with baseline and post-BD FVS parameters except post-BD FEV 1 /FVC, respectively, and post-BD Xrs5 showed a strong correlation with post-BD FVC (ρ = 0.61) and post-BD FEV 1 (ρ = 0.59). In adjusted linear regression, preschool Xrs5 remained as a statistically significant independent predictor of FVS parameters in adolescence; the one-unit decrease in the Z-score of preschool post-BD Xrs5 predicted 9.6% lower post-BD FEV 1 , 9.3% lower post-BD FVC, and 9.7% lower post-BD MEF 50 when expressed as %-predicted parameters., Conclusion: Persistent post-BD small airway impairment in children with a history of bronchiolitis detected with IOS at preschool age predicted FVS results measured in early adolescence., (© 2018 Wiley Periodicals, Inc.)

Recent studies revealed common genetic risks for both viral bronchiolitis and asthma. Genome-wide association studies revealed that rs7216389 in the ORMDL3 gene is associated with childhood asthma. We conducted a case-control study examining the associations between ORMDL3 polymorphisms (rs7216389, rs12603332, and rs11650680) and bronchiolitis susceptibility/viral findings among 247 infant bronchiolitis cases and 190 healthy controls. We genotyped single nucleotide polymorphisms by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry and detected respiratory viruses with multiplex reverse transcriptase-polymerase chain reaction. Only the genotype and allele frequencies of rs7216389 significantly differed between bronchiolitis and controls. The frequencies of the TT homozygote and the T allele of rs7216389 were significantly higher in the bronchiolitis patients (P = 0.0325; P = 0.0089, respectively). Polymorphisms were not associated with bronchiolitis severity. Cases were further stratified by viral infection, but no significant differences in the ORMDL3 genotype between the virus-detected group (e.g., respiratory syncytial virus alone, respiratory virus alone, virus detected) and no-virus-detected group were observed. Bronchiolitis is associated with the ORMDL3 gene in Chinese children, and there were no significant associations between genetic variations and disease severity or respiratory viruses. The TT homozygote and the T allele of rs7216389 in ORMDL3 increased bronchiolitis risk. The rs7216389 polymorphism may be a predictor for identifying infants with predisposition to virus-induced wheezing to persistent asthma.

Background: The fraction of exhaled nitric oxide (FeNO) has been suggested as a non-invasive marker of eosinophilic inflammation in asthma, but lately rather as a biomarker of atopy than of asthma itself. Asthma after bronchiolitis is common up to early adolescence, but the inflammation and pathophysiology may differ from other phenotypes of childhood asthma. We aimed to assess if FeNO was different in children with former hospitalization for bronchiolitis and a control group, and to explore whether the role of FeNO as a marker of asthma, atopy or bronchial hyperresponsiveness (BHR) differed between these two groups of children., Methods: The study included 108 of 131 children (82%) hospitalized for bronchiolitis in 1997-98, of whom 82 (76%) had tested positive for Respiratory syncytial virus, and 90 age matched controls. The follow-up took place in 2008-2009 at 11 years of age. The children answered an ISAAC questionnaire regarding respiratory symptoms and skin prick tests, spirometry, methacholine provocation test and measurement of FeNO were performed., Results: Analysed by ANOVA, FeNO levels did not differ between the post-bronchiolitis and control groups (p = 0.214). By multivariate regression analyses, atopy, height (p < 0.001 for both) and BHR (p = 0.034), but not asthma (p = 0.805) or hospitalization for bronchiolitis (p = 0.359), were associated with FeNO in the post-bronchiolitis and control groups. The associations for atopy and BHR were similar in the post-bronchiolitis and in the control group., Conclusion: FeNO did not differ between 11 year old children hospitalized for bronchiolitis and a control group. FeNO was associated with atopy, but not with asthma in both groups.

The association between bronchiolitis in the first year of life and subsequent asthma, atopy, airway obstruction and bronchial hyper-responsiveness (BHR) is unsettled. Genetic predispositions, pre-morbid lung function, environmental interactions and altered immunological responses are risk factors that have been studied. The aim of this study was to assess lung function, BHR and the occurrence of asthma and atopy 11 yr after hospitalization for bronchiolitis in the first year of life, particularly focusing on the role of gender and virus involved. The study included 121 of 131 (92%) children hospitalized for bronchiolitis, 90 (74%) respiratory syncytial virus (RSV)-positive children and 141 children in an age-matched and unselected control group. At follow-up, current asthma was more common after RSV-negative bronchiolitis compared to controls (35.5% vs. 9.2%; p < 0.001), but not after RSV bronchiolitis (15.6%; p = 0.144). Higher BHR and an obstructive lung function pattern were observed after bronchiolitis, the latter most prominent after RSV-negative bronchiolitis. Higher BHR was confined to boys, but present in both the RSV-positive and RSV-negative groups (p = 0.007 and 0.003, respectively). Asthma after bronchiolitis was not associated with atopy. Atopy was similarly distributed between the RSV-positive and RSV-negative bronchiolitis groups and the control group. This study has shown that gender and type of virus are important factors to consider when addressing later development of asthma, BHR and lung function after hospitalization for bronchiolitis in early life., (© 2012 John Wiley & Sons A/S.)

Asthma risk is lower after wheezing associated with respiratory syncytial virus (RSV) than with non-RSV infection in infancy. RSV is the main wheezing-associated virus in infants aged <6 months. We evaluated the outcome of children hospitalised for bronchiolitis at <6 months of age, with special focus on viral aetiology and early risk factors. Out of 205 infants hospitalised for bronchiolitis at <6 months of age, 127 (62%) attended a control visit at a mean age of 6.5 yrs and the parents of an additional 39 children were interviewed by telephone. Thus, follow-up data collected by identical structured questionnaires were available from 166 (81%) children. Viral aetiology of bronchiolitis, studied on admission by antigen detection or PCR, was demonstrable in 97% of cases. Current asthma was present in 21 (12.7%) children: 8.2% in the 110 former RSV patients versus 24% in non-RSV patients (p=0.01). 45 (27%) children had ever had asthma. In adjusted analyses, atopic dermatitis, non-RSV bronchiolitis and maternal asthma were independently significant early-life risk factors for asthma. The risk of asthma was lower after RSV bronchiolitis than after bronchiolitis caused by other viruses in children hospitalised at <6 months of age.

A wheeze is a high-pitched, musical, continuous sound that originates from oscillations in narrowed airways. Wheezing is most often the result of bronchiolitis in infants and asthma in older children. This article will discuss the similarities and differences between these two childhood diseases, along with management of the infant or child with wheezing.

A 56-year-old woman was referred to our hospital because of dyspnea, wheezing, and a productive cough. Eight years before presentation, bronchial asthma was diagnosed and the patient received inhaled corticosteroids plus antiasthmatic agents (a long-acting inhaled beta2-agonist, leukotriene modifiers, and theophylline). Chest radiography showed small diffuse nodular shadows, and a computed tomographic scan showed thickening of the bronchi and bronchioles, with diffuse centrilobular nodules in both lung fields. A blood test and microscopic examination of the bronchoalveolar fluid revealed marked eosinophilia. Transbronchial lung biopsy and transbronchial biopsy showed eosinophilic bronchitis and bronchiolitis. After treatment with oral prednisolone (40 mg daily) and inhaled corticosteroids, the symptoms, blood eosinophilia, and radiographic findings improved. Recently, several similar cases of eosinophilic bronchiolitis have been reported. Studies of further cases and elucidation of the pathophysiology of eosinophilic bronchiolitis are necessary to establish a concept for this disease and to determine whether it should be classified as a subtype of bronchial asthma or as a distinct entity.

Although eosinophilia in wheezing infants predicts subsequent wheezing, it is not known how long the association persists. Our aim was to evaluate the connection between blood eosinophilia in infancy and later wheezing/asthma until adulthood, with special attention paid to infection-induced changes in blood eosinophils. We have prospectively followed up 83 infants until adulthood after hospitalization for bronchiolitis in 1981-1982. Blood eosinophils were determined in a counting chamber on admission and on convalescence 4-6 weeks later. Data on recurrent wheezing and asthma were registered prospectively at five follow-ups until the age of 18-20 years. The median (25th-75th percentile) eosinophil count was 0.100 x 10E9/L (0.028-0.321) on admission and 0.231 x 10E9/L (0.119-0.368) on convalescence. Eosinophils during bronchiolitis or infection-induced changes in eosinophils were not associated with subsequent wheezing/asthma at any age during the follow-up. The result was similar in univariate and multivariate analyses. Respiratory syncytial virus (RSV) bronchiolitis patients had lower eosinophils on admission than non-RSV cases, but the changes induced by RSV or other infection did not differ significantly. In univariate analyses, elevated eosinophils on convalescence predicted later wheezing until 3-4 years of age. In multivariate analysis, adjusted for RSV etiology, age on admission, and histories of earlier wheezing and atopy, elevated eosinophils on convalescence predicted increased asthma risk at 2-3 years (OR, 2.26; 95% CI, 1.29-3.95), at 3-4 years (OR, 2.24; 95% CI, 1.27-3.95), and at 8.5-10 years (OR, 2.16; 95% CI, 1.01-4.64). Eosinophilia outside, but not during, infection predicted recurrent wheezing until preschool and early school years but not thereafter.

In the present cohort, 85% of infants hospitalized for wheezing outgrew their symptoms until puberty, but 30-40% had asthma, depending on criteria, again in young adulthood. The aim of this study was to determine early predictors for adulthood asthma, bronchial reactivity, and lung function abnormalities in infants hospitalized for bronchiolitis. Fifty-two children hospitalized for bronchiolitis at < 2 years of age were restudied at the median age of 19 years. Wheezing histories and early risk factors for later asthma were recorded prospectively during infancy. The follow-up study consisted of a written questionnaire, physical examination, flow-volume spirometry, methacholine inhalation challenge, home peak expiratory flow monitoring, and skin-prick tests. In univariate analyses, parental asthma and repeated wheezing at age the age of 0-1 years and 0-2 years predicted adulthood asthma. Repeated wheezing at age the age of 0-1 years predicted later bronchial reactivity. Onset and recurrence of wheezing at < 1 year of age, parental atopy and asthma, and maternal smoking during infancy were related to subnormal lung function parameters. In multivariate logistic regression, adjusted for sex, age on admission, current smoking, and atopy in infancy and, currently, repeated wheezing both at < 1 year and < 2 years of age was an independent predictor for adulthood asthma. Parental asthma and repeated wheezing predict adulthood asthma in infants hospitalized for bronchiolitis, and maternal smoking predisposes them to lung function impairment in adulthood.

Background: The relationship between early infections due to respiratory syncytial virus (RSV), particularly bronchiolitis in infancy, and the subsequent development of asthma, bronchial hyper-responsiveness, and/or other allergic manifestations, seems increasingly certain, even if the mechanisms involved are not yet quite clear., Objectives: The objectives of this work were to determine the prevalence of, and risk factors for, asthma and allergy in 5 to 6 year-old children who five years previously, had experienced their first episode of bronchiolitis before the age of twelve months, and to define the possible effect of the age at which the bronchiolitis occurred on the subsequent development of asthma., Method: A retrospective cohort survey was conducted, based on the registers of two hospital paediatric emergency units (Unit A: the Ambroise Pare teaching hospital at Boulogne, France and unit B: the General Hospital of Cherbourg, France). The cohort comprised 5-6 years old children who had consulted or been admitted to emergency unit A or B between October 1993 and March 1994 for a first attack of bronchiolitis before the age of 12 months., Results: One hundred and twenty eight children were included in the two centres (centre A: 78; centre B: 50). A familial history of allergy was found in 92 children (71.8%). Fifty-two (40.6%) were exposed to tobacco smoke. One hundred and five children (81.2%) had been hospitalised during the first episode of bronchiolitis, but none had been placed in intensive care. Their mean age at admission was 5.1 months, and 29 children were less than three months old. Ninety seven children (75.8%) had experienced at least one episode of wheezing at some time of their life. In the twelve months before the telephone interview, 40 children (31.3%) had had at least one such episode, 47 (36.7%) an attack of asthma, 32 (25.0%) wheezing after an effort, 43 (39.4%) a dry cough at night, 52 children (40.6%) had exhibited allergic rhinitis signs, and 32 (25.0%) eczema. Among the 47 children who had experienced at least one attack of asthma during the previous twelve months, 27 (57.4%) had a history of familial asthma (p<0.04). This was the only significant relationship observed in this study with regard to risk factors for asthma. No relationship was observed between asthma or recent wheezing on the one hand, and on the others age less than three months during the first bronchiolitis episode (p=0.6), initial hospital admission (p=0.6) tobacco smoke exposure (p=0.27), sex (p=0.10) or day care management until age three (p=0.73)., Discussion: This study showed a high prevalence of asthma and other allergic manifestations in children who five years previously, had experienced their first bronchiolitis episode before the age of twelve months. The only risk factor for asthma or chest wheezing identified in this study was a familial history of allergy. These data support the idea that for most children, early acute bronchiolitis, even if severe, is a transient event, with no or very few consequences in the middle or long term. Nevertheless it may be the expression of an interaction between viral infection and atopic familial predisposition leading to lasting bronchial hyper-responsiveness.

Histologic and imaging studies show that asthmatic inflammation occurs in small airways of the peripheral lung, even in patients with mild disease. Small airway inflammation leads to obstruction that can be detected as peripheral resistance, air trapping, and eosinophil infiltration and is manifested clinically as nocturnal asthma and frequent exacerbations. Inflammatory activity in the distal lung of patients may actually exceed that of the large airways. Anatomic changes in small airways are prominent in cases of fatal asthma.

Heliox is composed of oxygen and helium and its low specific gravity allows a modification of the gas flow within the airway. Breathing heliox favors a laminar flow and therefore decreases the work of breathing. Its usefulness in the child is established in croup or in post-extubation stridor. It can be considered if conventional treatment fails to improve the child's breathing pattern. Its major goal is to avoid invasive manoeuvers as much as possible.

Analogous to childhood-onset asthma in humans, rats may develop a chronic asthmalike phenotype, depending on their genetic background and the age at which they experience a viral airway injury. Brown Norway rats develop a postbronchiolitis asthmalike phenotype that may be prevented with supplements of interferon-gamma (IFN-gamma); we hypothesized that the normally resistant F344 rat strain would develop the asthmalike phenotype if the IFN-gamma response were suppressed during viral illness. Weanling F344 rats were pretreated with anti-IFN-gamma or control antibody, and inoculated with Sendai virus or vehicle. Anti-IFN-gamma treatment reduced lung IFN-gamma and increased IL-4 mRNA during the infection. Physiologic studies performed 8 wk later revealed premature airway closure (p = 0.03) and elevated specific pulmonary resistance (p < 0.01) in the postbronchiolitis anti-IFN-gamma group compared with noninfected controls and untreated postbronchiolitis rats. However, unlike the postbronchiolitis asthmalike phenotype in Brown Norway rats, bronchiolar inflammation and fibrosis were absent in the F344 rats. Lung elastic recoil and alveolar surface density also were unchanged compared with noninfected control rats. We conclude that there is an interactive effect of a weak IFN-gamma response and viral bronchiolitis at an early age that may result in persistent postbronchiolitis airway dysfunction. The presence of premature airway closure that is independent of airway wall inflammation or changes in lung elastic recoil suggests peripheral airway instability as a mechanism for the airway obstruction.

Study Objectives: To evaluate the relationship between bronchial hyperresponsiveness (BHR) in infants with wheezing and the subsequent development of asthma., Intervention: Bronchial reactivity to inhaled methacholine (BRm) during the infantile period was studied using the transcutaneous partial pressure of oxygen (tcPO(2)) method. Children were followed long-term for the development of asthma., Patients: Fourteen children with bronchiolitis (mean age, 0.7 years) and 48 with wheezy bronchitis (mean age, 2.3 years) were enrolled. For comparison, 40 children with asthma (mean age, 4.6 years) and 27 healthy control subjects without chronic respiratory disease (mean age, 2.7 years) were studied., Measurements: Consecutive doses of methacholine were doubled until a 10% decrease in tcPO(2) from baseline was reached. The cumulative dose of methacholine (Dmin) at the inflection point of tcPO(2) (Dmin-PO(2)) was recorded., Results: During > 10 years of follow-up, seven patients with bronchiolitis developed asthma and all patients in the higher BRm set developed asthma, compared with none in the lower BRm set. In the wheezy bronchitis group, Dmin-PO(2) values in the 32 patients who developed asthma were lower than those in patients who had not developed asthma (p < 0.001)., Conclusions: We concluded that there is a tendency for infants with a clinical diagnosis of bronchiolitis or wheezy bronchitis and who show BHR in the infantile period to develop asthma. The presence of increased BHR after infantile respiratory diseases associated with wheezing may be a prelude to the development of childhood asthma.

Infants are at increased risk of developing asthma after acute bronchiolitis. We assessed the hypothesis that cytokine production is related to the development of asthma after bronchiolitis. The smoking history and the presence of atopy or asthma in parents or siblings were recorded and blood mononuclear cell interferon (IFN)-gamma and interleukin (IL)-4 production in response to IL-2 were assessed in 32 infants hospitalized for bronchiolitis and in a subgroup (n = 19) in which pulmonary function tests were performed approximately 4.9 mo later. The presence of asthma was determined by the Delphi consensus method 2 yr after hospitalization. Infants were classified as follows: asthma absent (A, n = 14), possible (Po, n = 9), or probable (Pr, n = 9). Infants with possible and probable asthma had lower IFN-gamma production at the time of bronchiolitis and a trend to lower IFN-gamma production 4.9 mo later when compared with those who had no asthma. At the time of bronchiolitis, IFN-gamma production was: 123 +/- 31 versus 34 +/- 20 versus 21 +/- 14 pg/ml, A versus Po versus Pr (p = 0.02, ANOVA) and 4.9 mo after bronchiolitis, IFN-gamma production was: 147.3 +/- 45 versus 47.4 +/- 30 versus 22.3 +/- 32 pg/ml, No versus Po versus Pr (p = 0.08 ANOVA). IL-4 production did not differ between groups. Infants who went on to develop asthma had more parent smokers (21.4% versus 55. 6% versus 55.6%, A versus Po versus Pr, p < 0.04), lower VmaxFRC (122 +/- 18 versus 77 +/- 7 versus 67 +/- 8% predicted, A versus Po versus Pr, p < 0.02), lower PC40 histamine (6.4 +/- 3.3 versus 1.2 +/- 0.6 mg/ml, A versus Po+Pr, p < 0.03) but no increase in atopy or asthma in their family. Significant positive correlations were found between IFN-gamma production at the time of bronchiolitis and VmaxFRC (r = 0.606) or PC40 histamine (r = 0.648) 4.9 mo after bronchiolitis. Lower IFN-gamma production at the time of bronchiolitis is an indicator of lower pulmonary function and increased responsiveness to histamine 4.9 mo after bronchiolitis and is related to the development of asthma after bronchiolitis in infants.

Ambulatory peak flow monitoring plays an important role in the diagnosis and management of patients with bronchial asthma. Today several kinds of portable peak flow meters (PFMs) are available for this purpose and sometimes comparisons between the readings of different kinds of PFMs are necessary in clinical setting. We compared four types of PFMs in patients with various respiratory diseases. The study population consisted of 294 patients with asthma, chronic obstructive pulmonary disease, diffuse panbronchiolitis and other respiratory systems, and 15 healthy volunteers. Initially, subjects underwent a spirometry until at least three acceptable forced expiratory curves were obtained. Thereafter each subject blew into a Mini-Wright meter, Assess meter, Pulmo-graph meter and Wright Pocket meter, three times in a random order, with an interval of 4 min. The highest value of three blows was recorded in each PFM measurement. Finally, a second set of spirometric measurements were obtained. Spirometric peak flow rates (PEFRs) were obtained from the best single test which gave the largest sum of forced vital capacity and forced expiratory volume in 1 s (FEV1). In cases when FEV1 in the first spirometry examination was less than 11 or the readings of the PFM were less than 3501 min-1, low-range PFMs were used. The second spirometric PEFR was used as a standard against which the reading of the PFM was compared. The correlation coefficients between the readings of each PFM and spirometric PEFR did not differ significantly from each other. The limits of agreement between each PFM were very wide. In both low- and standard-range PFM, the Assess meter had a significantly greater absolute difference from the spirometric PEFR than other PFMs. In the standard range, the Wright Pocket meter also had a greater difference than the Pulmo-graph meter. The standard-range Assess meter tended to lose its strength of correlation with the spirometric measurement at higher flow rates as did the low-range Pulmo-graph and Mini-Wright meters at the lower and higher flow rates, respectively. All four types of standard-range PFMs gave similarly valid values when spirometric PEFR was used as a reference. However, the limit of agreement between each PFM is so wide that we do not recommend the use of the readings of each meter interchangeably.

The American Thoracic Society (ATS) and the European Respiratory Society (ERS) recommend that the largest forced vital capacity (FVC) and the largest forced expiratory volume in 1 s (FEV1) should be recorded from at least three acceptable curves independently which curve they came from. Although these recommendations have been used for decades, there is still some controversy over their validity. The purpose of this study was to determine how the intersession variability of reported FVC and FEV1 values is influenced by different methods of selection in clinical practice. The study population consisted of 283 patients with obstructive airway diseases. Spirometry was performed until three acceptable forced expiratory curves were obtained in the standing position. A second set of spirometric measurements was obtained approximately 30 min after the first set of measurements. The following sampling methods were compared: method A, the largest FVC and the largest FEV1 among all three acceptable curves (ATS-ERS recommendation); method B, the FVC and the FEV1 from the single curve that yielded the largest sum of FVC plus FEV1 (best test); method C, the average of all three acceptable curves; method D, the average of the largest two FVCs and FEV1s among all of the three acceptable curves. FVC and FEV1 determined by method B gave almost identical values to those obtained by method A in most cases. However, method A was least variable for FEV1. In addition, the differences in FEV1 values between these two methods were large in some of patients with chronic obstructive pulmonary disease. The other selection criteria compared in this study offer no clear-cut advantages over method A. The ATS ERS recommended method appeared to be slightly more reproducible than the other selection criteria, including the 'best test' method, and should therefore be the preferred method of choice.

Over a period of 12 months from 1981 to 1982, 83 patients aged less than 2 years were treated in hospital for acute bronchiolitis. The children were followed-up prospectively; 68 (83%) completed the study until 4.5-6.0 years of age. At this age, 17 (25%) of the 68 children with bronchiolitis still suffered from wheezing attacks. These 17 asthmatics suffered from both atopic dermatitis (29 versus 6%) and allergic rhinitis (29 versus 8%) more frequently than non-asthmatic children. In contrast, positive results in the skin prick tests were almost equally common (29 and 20%) in asthmatic and non-asthmatic children. In these tests, allergies to birch pollen, timothy grass pollen and house dust mite were most common; asthma was particularly associated with house dust mite allergy. The presence of atopic dermatitis, elevated immunoglobulin E values and repeated wheezing episodes between 1 and 2 years of age were significant risk factors for later asthma. In conclusion, the risk for later asthma is increased after early childhood bronchiolitis; the frequency of asthma was 25% in the present study. Our results confirm that atopics are at a greater risk of developing asthma later in childhood than non-atopics; the risk was significant from 1 year of age onwards.

The term bronchiolitis refers to the presence of an inflammatory response in the respiratory bronchioles. This article summarizes the current general agreement that the inflammatory process present in bronchiolitis is responsible for the changes seen in the airways in both asthma and chronic obstructive pulmonary disease (COPD).

A 19-year-old woman presented with lifelong asthma. Pulmonary function studies revealed a mixed restrictive-obstructive pattern, with significantly decreased elastic recoil as demonstrated by a pressure-volume study. Upon administration of inhaled bronchodilator, however, the patient's lung volume and compliance returned to normal, illustrating the rare phenomenon of reversible restrictive lung disease. Open lung biopsy revealed respiratory bronchiolitis, confirming the suspected involvement of small airways. Mechanisms of reversible restriction, specifically alveolar duct constriction, are discussed. The authors speculate on the observed relation between anatomic and physiologic abnormalities.

We studied the effect of the weather on acute exacerbations of bronchial asthma in children by comparing records of 8,657 admissions for five acute respiratory diseases (3,064 for asthma) with concurrent meteorologic data. These diseases were classified according to their interrelations and distinct meteorologic patterns into two groups: (1) acute asthma and acute laryngitis, which are correlated with the afternoon gradients of air temperature, heat content (the thermal energy of the ambient air), and modified heat content factor (the energy required to heat the air water vapor to the ambient temperature), but not correlated with the absolute values of air temperature and water content: and (2), bronchopneumonia/pneumonia and upper respiratory infections, which are correlated only with the absolute values of the meteorologic parameters (air temperature, water content, heat content, and modified heat content factor), but not with their afternoon gradients. Admissions for bronchiolitis revealed an age-related pattern: up to 1 yr they resembled Group 2 and from 1 to 2 yr, Group 1. It follows that the admission rates of acute exacerbation of bronchial asthma in childhood are linked both to the afternoon weather gradients and to some of the acute respiratory infections.