Management of sleep-disordered breathing in patients with syndromic hemifacial macrosomia.

PURPOSE: Patients with syndromic hemifacial microsomia (SHFM) are at risk of obstructive sleep apnea (OSA). The aim of the study was to describe the prevalence of OSA and its management, especially in patients with Goldenhar syndrome (GS). METHODS: The respiratory polygraphies and clinical management of 15 patients, aged 2 to 23 years, evaluated at a national reference center, were analyzed. RESULTS: Four (27%) patients had no OSA, 4 (27%) had mild OSA, and 7 (46%), of whom 5 were ≤ 2 years old, had severe OSA. None of the patients had central apneas. Only one patient had alveolar hypoventilation, and another one had nocturnal hypoxemia. Two patients had severe OSA despite prior adenoidectomy or mandibular distraction osteogenesis. Median duration of follow-up was 3.5 years (range 0.5-9 years). None of the patients without OSA or with mild OSA at baseline respiratory polygraphy developed OSA during the follow up. Among the 7 patients with severe OSA, 3 required continuous positive airway pressure or noninvasive ventilation, and one patient required a tracheostomy. CONCLUSION: In conclusion, patients with SHFM are at high risk of severe OSA at any age, underlining the importance of systematic sleep studies to diagnose and evaluate the severity of OSA. Individualized treatment should be privileged, based on a careful examination of the entire upper airway, taking in account potential associated risk factors. All patients with SHFM should be managed by a pediatric expert multidisciplinary medical/surgical team until the end of post pubertal growth.

Pediatric Sleep Respiratory Disorders: A Narrative Review of Epidemiology and Risk Factors.

Sleep is a fundamental biological necessity, the lack of which has severe repercussions on the mental and physical well-being in individuals of all ages. The phrase "sleep-disordered breathing (SDB)" indicates a wide array of conditions characterized by snoring and/or respiratory distress due to increased upper airway resistance and pharyngeal collapsibility; these range from primary snoring to obstructive sleep apnea (OSA) and occur in all age groups. In the general pediatric population, the prevalence of OSA varies between 2% and 5%, but in some particular clinical conditions, it can be much higher. While adenotonsillar hypertrophy ("classic phenotype") is the main cause of OSA in preschool age (3-5 years), obesity ("adult phenotype") is the most common cause in adolescence. There is also a "congenital-structural" phenotype that is characterized by a high prevalence of OSA, appearing from the earliest ages of life, supported by morpho-structural abnormalities or craniofacial changes and associated with genetic syndromes such as Pierre Robin syndrome, Prader-Willi, achondroplasia, and Down syndrome. Neuromuscular disorders and lysosomal storage disorders are also frequently accompanied by a high prevalence of OSA in all life ages. Early recognition and proper treatment are crucial to avoid major neuro-cognitive, cardiovascular, and metabolic morbidities.

Primary ciliary dyskinesia: A multicenter survey on clinical practice and patient management in Italy.

INTRODUCTION: There are no recent data on primary ciliary dyskinesia (PCD) distribution, diagnosis and treatment in Italy. METHODS: A descriptive study based on a survey questionnaire. It consisted of three sections (patients, diagnosis, and treatment), and sent to all the Italian PCD Centers. RESULTS: Questionnaires obtained from 20/22 centers in 12/20 regions showed that the total number of PCD patients treated at the participating centers was of 416. Out of all centers, 55% follow <20 patients, two centers have >40 patients, and 75% follow both pediatric and adults. Age at diagnosis was between 4 and 8 years in 45% of the centers, <3 years in three centers. Nasal nitric oxide, transmission electron microscopy and ciliary high-speed video microscopy are performed in 75%, 90%, and 40% of centers, respectively. Immunofluorescence is available in five centers. Genetic analysis is offered in 55% of the centers, and in seven centers >50% of the patients have a known genetic profile. Patients treated at all centers receive inhaled saline solutions, corticosteroids and chest physiotherapy. Prophylactic antibiotics and mucolytics are prescribed in 95% and 50% of the centers, respectively. Pseudomonas infection is treated with oral or inhaled antibiotics. CONCLUSIONS: Many Italian centers care for a small number of pediatric and adult patients, and diagnosis is often delayed. We found a great variability in the available diagnostic procedures, as well in the prescribed therapies. Our study will help to uniform diagnostic algorithm and share treatments protocols for PCD in Italy and allowed to set specific national goals.

Using electrical impedance tomography to characterize lung impairment of children with primary ciliary dyskinesia: A pilot cross-sectional study.

BACKGROUND: In children with primary ciliary dyskinesia (PCD), measures more sensitive than spirometry are needed to characterize underlying pulmonary impairment. Electrical impedance tomography (EIT) is a promising noninvasive method for monitoring the distribution of lung ventilation, and it does not require patient collaboration. We aimed to provide an assessment of the feasibility and clinical usefulness of EIT in characterizing lung impairment in children with PCD, compared to spirometry and multiple breath nitrogen washout (MBWN2 ) test. METHODS: Children and adolescents with PCD underwent MBWN2 test as first respiratory assessment, followed by EIT monitoring and spirometry during outpatient follow-up. RESULTS: We included 12 out of 16 individuals regularly followed at our clinic. A total of 41.7% (5/12) showed abnormal forced expiratory volume in 1 s (FEV1 ), whereas 11/12 (91.7%) had abnormal ventilation inhomogeneity measured with MBWN2 test. Using EIT, the global inhomogeneity (GITOT ) index showed moderate to strong correlation with FEV1 (ρ = -0.55, 95% confidence interval [CI]: -0.87 to 0.02) and ranged from 37 to 44, with the highest inhomogeneity detected in the dorsal right quadrant. GITOT was moderately correlated with RV/TLC %predicted (ρ = 0.38, 95% CI: -0.17 to 0.74), while we detected a weak correlation between GITOT and lung clearance index (ρ = 0.29, 95% CI: -0.45 to 0.82). CONCLUSION: EIT appears promising as a noninvasive technique to characterize ventilation distribution in children with PCD, thus providing a complementary assessment to static and dynamic lung function measures of PCD disease.

Modulating Role of Breastfeeding Toward Long COVID Occurrence in Children: A Preliminary Study.

The SARS-CoV-2 (Severe acute respiratory syndrome Coronavirus-2) pandemic has forced the global health system to face new challenges both in the acute management of COVID-19 (Coronavirus Disease 2019) patients and in its consequences. In particular, the long-term effects of this new virus, especially in children, are still poorly understood. Scientific research is currently trying to understand the mechanisms underlying the so called "long COVID syndrome". Since the beginning of the pandemic, breastmilk has been studied for its antiviral and immunomodulatory properties. Based on these assumptions, we conducted a preliminary study in order to investigate the prevalence of long COVID in a cohort of Italian children with previously detected SARS-CoV-2 infection and evaluate if breastfeeding might play a role in modulating long COVID occurrence.

Caregivers' Attitudes Toward COVID-19 Vaccination in Children and Adolescents With a History of SARS-CoV-2 Infection.

Background: Limited data are available on the attitudes of caregivers toward COVID-19 vaccination in children and adolescents with a history of SARS-CoV-2 infection or Long Covid symptoms. The aim of this study was to investigate the vaccine hesitancy among caregivers of children and adolescents with a documented history of SARS-CoV-2 infection and to explore the possible associations between COVID-19 manifestations and the acceptance of the vaccine. Methods: Caregivers of children or adolescents with a microbiologically confirmed diagnosis of SARS-CoV-2 infection evaluated in two University Hospitals were interviewed. Results: We were able to contact 132 caregivers and 9 declined to participate. 68 caregivers (56%) were in favor of COVID-19 vaccination for their child. In the multiple logistic regression, child's age (OR 1.17, 95%CI 1.06-1.28) and hospitalization due to COVID-19 (OR 3.25, 95%CI 1.06-9.95) were positively associated with being in favor of COVID-19 vaccination. On the contrary, the occurrence of child's Long Covid was associated with a higher likelihood of being against the vaccination (OR 0.28, 95%CI 0.10-0.80). Conclusions: This preliminary study shows that only about half of the interviewed parents of children and adolescents with a previous SARS-CoV-2 infection are willing to vaccinate them to prevent a repeated COVID-19 infection. These findings might help healthcare workers to provide tailored information to caregivers of children with a previous SARS-CoV-2 infection.

Therapeutic Strategies for COVID-19 Lung Disease in Children.

The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection has milder presentation in children than in adults, mostly requiring only supportive therapy. The immunopathogenic course of COVID-19 can be divided in two distinct but overlapping phases: the first triggered by the virus itself and the second one by the host immune response (cytokine storm). Respiratory failure or systemic involvement as Multisystem Inflammatory Syndrome in Children (MIS-C) requiring intensive care are described only in a small portion of infected children. Less severe lung injury in children could be explained by qualitative and quantitative differences in age-related immune response. Evidence on the best therapeutic approach for COVID-19 lung disease in children is lacking. Currently, the approach is mainly conservative and based on supportive therapy. However, in hospitalized children with critical illness and worsening lung function, antiviral therapy with remdesivir and immunomodulant treatment could be considered the "therapeutic pillars."

Sleep disordered breathing and daytime hypoventilation in a male with MECP2 mutation.

Rett syndrome (RTT, MIM * 312750) is an X-linked neurodevelopmental disorder caused by pathogenic variants at the Xq28 region involving the gene methyl-CpG-binding protein 2 (MECP2, MIM * 300005). The spectrum of MECP2-related phenotypes is wide and it ranges from asymptomatic female carriers to severe neonatal-onset encephalopathy in males. Abnormal breathing represents one of the leading features, but today little is known about polysomnographic features in RTT females; no data are available about males. We report the case of a male of Moroccan origins with a MECP2 pathogenic variant and a history of encephalopathy and severe breathing disturbances in the absence of dysmorphic features. For the first time we describe in detail the polysomnographic characteristics of a MECP2-mutated male and we show the relevance of severe central apneas, which may represent a new clinical clue to suggest the diagnosis. Moreover, we want to highlight the importance to maintain a high index of suspicion for MECP2-related disorders in the presence of severe hypotonia, apneic crises, and respiratory insufficiency in males to permit an earlier diagnosis and the consequent definition of recurrence risk of the family and to avoid other useless and invasive exams.

Familial Sleep Disorders in Unknown Genetic Syndrome.

Sleep-disordered breathing (SDB) is common in children, especially in those with congenital or genetic diseases. The factors involved include obstructive sleep apnea, disrupted rapid eye movement sleep, and central hypoventilation. Diagnosing and treating SDB in these children have a positive impact on the quality of life of them and their families, reducing the risk of both further impairment of cognitive abilities and cardiopulmonary complications. We report a familial case of SDB with central hypoventilation, in which identification of the disorder in the younger sister led to the unfortunately late diagnosis and treatment of the same condition in the older sister.

When and how ruling out cystic fibrosis in adult patients with bronchiectasis.

BACKGROUND: Bronchiectasis is the final result of different processes and most of the guidelines advocate for a careful evaluation of those etiologies which might be treated or might change patients' management, including cystic fibrosis (CF). MAIN BODY: CFTR mutations have been reported with higher frequency in bronchiectasis population. Although ruling out CF is considered as a main step for etiological screening in bronchiectasis, CF testing lacks of a standardized approach both from a research and clinical point of view. In this review a list of most widely used tests in CF is provided. CONCLUSIONS: Exclusion of CF is imperative for patients with bronchiectasis and CFTR testing should be implemented in usual screening for investigating bronchiectasis etiology. Physicians taking care of bronchiectasis patients should be aware of CFTR testing and its limitations in the adult population. Further studies on CFTR expression in human lung and translational research might elucidate the possible role of CFTR in the pathogenesis of bronchiectasis.

Respiratory Morbidity in Children with Repaired Congenital Esophageal Atresia with or without Tracheoesophageal Fistula.

Congenital esophageal atresia with or without tracheoesophageal fistula (CEA ± TEF) is a relatively common malformation that occurs in 1 of 2500-4500 live births. Despite the refinement of surgical techniques, a considerable proportion of children experience short- and long-term respiratory complications, which can significantly affect their health through adulthood. This review focuses on the underlying mechanisms and clinical presentation of respiratory morbidity in children with repaired CEA ± TEF. The reasons for the short-term pulmonary impairments are multifactorial and related to the surgical complications, such as anastomotic leaks, stenosis, and recurrence of fistula. Long-term respiratory morbidity is grouped into four categories according to the body section or function mainly involved: upper respiratory tract, lower respiratory tract, gastrointestinal tract, and aspiration and dysphagia. The reasons for the persistence of respiratory morbidity to adulthood are not univocal. The malformation itself, the acquired damage after the surgical repair, various co-morbidities, and the recurrence of lower respiratory tract infections at an early age can contribute to pulmonary impairment. Nevertheless, other conditions, including smoking habits and, in particular, atopy can play a role in the recurrence of infections. In conclusion, our manuscript shows that most children born with CEA ± TEF survive into adulthood, but many comorbidities, mainly esophageal and respiratory issues, may persist. The pulmonary impairment involves many underlying mechanisms, which begin in the first years of life. Therefore, early detection and management of pulmonary morbidity may be important to prevent impairment in pulmonary function and serious long-term complications. To obtain a successful outcome, it is fundamental to ensure a standardized follow-up that must continue until adulthood.

Role of High-Resolution Chest Computed Tomography in a Child with Persistent Tachypnoea and Intercostal Retractions: A Case Report of Neuroendocrine Cell Hyperplasia.

Background: Chronic interstitial lung diseases in children (chILD) are a heterogeneous group of disorders that can represent a clinical challenge for pediatric pneumologists. Among them, neuroendocrine cell hyperplasia of infancy (NEHI) is a diffuse lung disease prevalent in the first years of life that spontaneously improves over time. The clinical presentation of NEHI is indistinguishable from other interstitial lung diseases, so a correct and non-invasive diagnosis by chest computed tomography (CT) without lung biopsy might not be simple. Case presentation: An 8-month-old male infant presented with a history of chronic tachypnoea and dyspnoea since 6 months of age. The patient was born at term, with APGAR scores of 9 and 10 at 1 and 5 min, respectively. Since his second month of life, the patient suffered from abnormal breathing, which was characterized by mild tachypnoea and costal retractions that worsened during breastfeeding, crying, and respiratory infections. Bilateral inspiratory crackles, preferential to the lung bases, without oxygen desaturation were detected. A chest X-ray showed a diffuse over-inflation of the lungs, but laboratory tests did not reveal any abnormalities. High-resolution chest CT documented patchy areas of ground-glass opacity involving the right upper lobe, middle lobe, and lingula, and showed mosaic areas of air-trapping, suggesting a diagnosis of NEHI. The infant was discharged without therapy and gradually improved over time. At 1 year of age, the patient was eupnoeic and chest auscultation had normalized. Conclusions: NEHI is an interstitial disease of infancy characterized by tachypnoea from the first months of life, with a good prognosis and for which a rational diagnostic approach is crucial for making a specific, early diagnosis. Initially, clinical suspicions can be confirmed with reasonable accuracy by a CT scan of the chest. Other more invasive and more expensive investigations should be reserved for selected cases that do not show a spontaneous, favourable clinical evolution.

Idiopathic pulmonary haemosiderosis in paediatric patients: how to make an early diagnosis.

BACKGROUND: Idiopathic pulmonary haemosiderosis (IPH) is a rare but potentially lethal condition in paediatric patients. This condition is considered an immune-mediated disorder, but its pathogenesis is still unknown. Idiopathic pulmonary haemosiderosis is characterized by the classical triad of haemoptysis, iron-deficiency anaemia, and diffuse parenchymal consolidation on chest radiology. Unfortunately, this triad of signs is not frequent in children at the onset of this disease, resulting in a delay in diagnosis and a negative outcome. CASE PRESENTATION: This case report describes a 4-year-old girl who was admitted for an acute episode of lower respiratory tract infection associated with severe dyspnoea, polypnoea, and severe anaemia (haemoglobin levels, 5.9 g/dL). She had a history of previous similar episodes, with anaemia treated unsuccessfully with iron supplementation and managed through repeated blood transfusions in the acute phase. She did not experience haemoptysis. A computed tomography (CT) scan of the thorax showed ground-glass opacity suggestive of pulmonary haemorrhage. After other causes of intra-alveolar haemorrhage were excluded, IPH was confirmed by the presence of siderophages in bronchoalveolar lavage. Immunosuppressive corticosteroid treatment was immediately started with a good clinical response. CONCLUSION: This case highlights the fact that IPH should be suspected in children with recurrent lower respiratory tract infections who have a history of iron-deficiency anaemia who shows no signs of improvement with iron supplementation and may require repeated blood transfusions. The absence of haemoptysis does not exclude the diagnosis of IPH in children. An early and prompt diagnosis is recommended in order to start adequate immunosuppressive treatment.

Children with recurrent pneumonia and non-cystic fibrosis bronchiectasis.

BACKGROUND: Recurrent pneumonia (RP) is one of the most frequent causes of pediatric non-cystic fibrosis (CF) bronchiectasis (BE) and a consequent accelerated decline in lung function. The aim of this study was to analyse the clinical records of children with RP in attempt to identify factors that may lead to an early suspicion of non-CF BE. METHODS: We recorded the demographic and clinical data, and lung function test results of children without CF attending our outpatient RP clinic between January 2009 to December 2013 who had undergone chest high-resolution computed tomography ≥ 8 weeks after an acute pneumonia episode and ≤ 6 months before enrolment. RESULTS: The study involved 42 patients with RP: 21 with and 21 without non-CF BE. The most frequent underlying diseases in both groups were chronic rhinosinusitis with post-nasal drip and recurrent wheezing (81 % and 71.4 % of those with, and 85.7 % and 71.4 % of those without BE). FEV1 and FEF25-75 values were significantly lower in the children with non-CF BE than in those without (77.9 ± 17.8 vs 96.8 ± 12.4, p = 0.004; 69.3 ± 25.6 vs 89.3 ± 21.9, p = 0.048). Bronchodilator responsiveness was observed in seven children with BE (33.3 %) and two without (9.5 %; p = 0.13). CONCLUSIONS: Reduced FEV1 and FEF25-75 values seem associated with an increased risk of developing non-CF BE in children with RP. This suggests a need for further studies to confirm the diagnostic usefulness use of spirometry in such cases.

Streptococcus pneumoniae colonisation in children and adolescents with asthma: impact of the heptavalent pneumococcal conjugate vaccine and evaluation of potential effect of thirteen-valent pneumococcal conjugate vaccine.

BACKGROUND: The main aim of this study was to evaluate Streptococcus pneumoniae carriage in a group of school-aged children and adolescents with asthma because these results might indicate the theoretical risk of invasive pneumococcal disease (IPD) of such patients and the potential protective efficacy of the 13-valent pneumococcal conjugate vaccine (PCV13). METHODS: Oropharyngeal samples were obtained from 423 children with documented asthma (300 males, 70.9%), and tested for the autolysin-A-encoding (lytA) and the wzg (cpsA) gene of S. pneumoniae by means of real-time polymerase chain reaction. RESULTS: S. pneumoniae was identified in the swabs of 192 subjects (45.4%): 48.4% of whom were aged <10 years, 46.9% aged 10-14 years, and 4.7% aged ≥15 years (p < 0.001). Carriage was significantly less frequent among the children who had received recent antibiotic therapy (odds ratio [OR 0.41]; 95% confidence interval [95% CI] 0.22-0.76). Multivariate analyses showed no association between carriage and vaccination status, with ORs of 1.05 (95% CI 0.70-1.58) for carriers of any pneumococcal serotype, 1.08 (95% CI 0.72-1.62) for carriers of any of the serotypes included in 7-valent pneumococcal conjugate vaccine (PCV7), and 0.76 (95% CI 0.45-1.28) for carriers of any of the six additional serotypes of PCV13. Serotypes 19 F, 4 and 9 V were the most frequently identified serotypes in vaccinated subjects. CONCLUSIONS: These results showed that carriage of S. pneumoniae is relatively common in all school-aged children and adolescents with asthma, regardless of the severity of disease and the administration of PCV7 in the first years of life. This highlights the problem of the duration of the protection against colonisation provided by pneumococcal conjugate vaccine, and the importance of re-colonization by the same pneumococcal serotypes included in the previously used vaccine.

Prevalence and Clinical Relevance of IgE Sensitization to Profilin in Childhood: A Multicenter Study.

BACKGROUND: Little is known about the prevalence and clinical relevance of hypersensitivity to the plant panallergen profilin in children. OBJECTIVES: The present study aimed to investigate prevalence, risk factors and clinical relevance of profilin sensitization in a large cohort of Italian children of different ages living in different geographic areas. METHODS: Children with pollen allergy enrolled by 16 pediatric outpatient clinics sited in three main geographic areas of Italy were studied. SPT were carried out with commercial pollen extracts and a commercial purified date palm pollen profilin. IgE specific for allergenic pollen molecules, Phl p 12 (grass profilin) and Pru p 3 (peach lipid transfer protein) were tested by ImmunoCAP FEIA. RESULTS: IgE to Phl p 12 (≥0.35 kU/l) was observed in 296 of the 1,271 participants (23%), including 17 of the 108 (16%) preschool children. Profilin SPT was positive (≥3 mm) in 320/1,271 (25%) participants. The two diagnostic methods were concordant in 1,151 (91%, p < 0.0001) cases. Phl p 12 IgE prevalence declined from northern to southern Italy and was directly associated with IgE to Phl p 1 and/or Phl p 5 and Ole e 1. Among children with IgE to Phl p 12, OAS was provoked by kiwi, melon, watermelon, banana, apricot and cucumber. CONCLUSIONS: Profilin sensitization is very frequent among pollen-allergic children, occurs at a very young age and contributes to the development of childhood OAS with a typical pattern of offending foods. Pediatricians should always consider IgE sensitization to profilin while examining pollen-allergic children, even if they are at preschool age.

Impact of genetic polymorphisms on paediatric atopic dermatitis.

In order to investigate whether polymorphisms of genes encoding some factors of innate and adaptive immunity play a role in the development of, or protection against atopic dermatitis (AD) and condition its severity, we genotyped 33 candidate genes and 47 single nucleotide polymorphisms (SNPs) using Custom TaqMan Array Microfluidic Cards and an ABI 7900HT analyser (Applied Biosystems, Foster City, CA, USA). The study involved 104 children with AD (29 with mild-to-moderate and 75 with severe disease; 42 girls; mean age ± SD, 5.8 ± 3.3 years) and 119 healthy controls (49 girls; mean age, 4.8 ± 3.0 years). IL10-rs1800872T, TG and MBL2-rs500737AG were all significantly more frequent among the children with AD (P = 0.015, P = 0.004 and P = 0.030), whereas IL10-rs1800896C and TC were more frequent in those without AD (P = 0.028 and P = 0.032). The VEGFA-rs2146326A and CTLA4-rs3087243AG SNPs were significantly more frequent in the children with mild/moderate AD than in those with severe AD (P = 0.048 andP = 0.036). IL10-rs1800872T and TG were significantly more frequent in the children with AD and other allergic diseases than in the controls (P = 0.014 and P = 0.007), whereas IL10-rs1800896TC and C were more frequent in the controls than in the children with AD and other allergic diseases (P = 0.0055 and P = 0.0034). These findings show that some of the polymorphisms involved in the immune response are also involved in some aspects of the development and course of AD and, although not conclusive, support the immunological hypothesis of the origin of the inflammatory lesions.

Impact of air pollution on respiratory diseases in children with recurrent wheezing or asthma.

BACKGROUND: Air pollution has many negative health effects on the general population, especially children, subjects with underlying chronic disease and the elderly. The aims of this study were to evaluate the effects of traffic-related pollution on the exacerbation of asthma and development of respiratory infections in Italian children suffering from asthma or wheezing compared with healthy subjects and to estimate the association between incremental increases in principal pollutants and the incidence of respiratory symptoms. METHODS: This prospective study enrolled 777 children aged 2 to 18 years (375 with recurrent wheezing or asthma and 402 healthy subjects). Over 12 months, parents filled out a daily clinical diary to report information about respiratory symptoms, type of medication used and healthcare utilization. Clinical data were combined with the results obtained using an air pollution monitoring system of the five most common pollutants. RESULTS: Among the 329 children with recurrent wheezing or asthma and 364 healthy subjects who completed follow-up, children with recurrent wheezing or asthma reported significantly more days of fever (p=0.005) and cough (p<0.001), episodes of rhinitis (p=0.04) and tracheitis (p=0.01), asthma attacks (p<0.001), episodes of pneumonia (p<0.001) and hospitalizations (p=0.02). In the wheezing/asthma cohort, living close to the street with a high traffic density was a risk factor for asthma exacerbations (odds ratio [OR]=1.79; 95% confidence interval [CI], 1.13-2.84), whereas living near green areas was found to be protective (OR=0.50; 95% CI, 0.31 -0.80). An increase of 10 µg/m3 of particulates less than 10 microns in diameter (PM10) and nitrogen dioxide (NO2) increased the onset of pneumonia only in wheezing/asthmatic children (continuous rate ratio [RR]=1.08, 95% CI: 1.00-1.17 for PM10; continuous RR=1.08, 95% CI: 1.01-1.17 for NO2). CONCLUSIONS: There is a significant association between traffic-related pollution and the development of asthma exacerbations and respiratory infections in children born to atopic parents and in those suffering from recurrent wheezing or asthma. These findings suggest that environmental control may be crucial for respiratory health in children with underlying respiratory disease.