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The objectives of this study were to determine the prevalence of chronic respiratory symptoms and asthma in 8- to 9-year-old children in Paris, and to analyze their medical management. This cross-sectional study was carried out in 1994 on a randomized sample of 3,756 pupils attending Paris public primary schools. The response rate by parents to an initial standardized self-administered questionnaire was 94.8%. This questionnaire identified 601 children (17%) as having recurrent respiratory symptoms. Of these children, 555 (92.3%) agreed to participate in a follow-up survey that evaluated their medical management; these children were examined by 73 school doctors of the city of Paris. Prevalence of parent-reported doctor-diagnosed asthma was 6.1%. In addition to these 211 children with asthma, 344 other children had recurrent respiratory symptoms: 120 children were “wheezers,” and the remaining 224 children were “coughers.” Among “chesty” pupils not identified as asthmatics, physical education teachers reported exercise-induced cough or respiratory discomfort in 13.7%, and nearly 14% had a peak expiratory flow 20% lower than the predicted values for age and height. In children identified as asthmatic, 25.3% were not under medical supervision, 55.5% had never performed lung function tests, 63.7% did not receive any prophylactic treatment, and 59.7% were receiving no treatment. Bronchodilator prophylactic medication before exercise was used by only 7% of asthmatics, although physical training teachers noted chest discomfort on exercise in 30.4% of these pupils. These results confirm that children with asthma and participating in this study were less than optimally investigated, were underdiagnosed and undertreated, and their medical management was not optimal. In addition to its epidemiologic value, the study has helped Paris school doctors to advise parents to refer their children to their general practitioner when asthma was suspected or undertreated. Pediatr Pulmonol. 1998; 26:106–112. © 1998 Wiley-Liss, Inc.

There is controversy as to whether low levels of air pollution affect the symptoms and lung function in asthma. We addressed this by examining the short-term effects of winter air pollution on childhood asthma in Paris. We performed a 6 month follow-up of 84 medically diagnosed asthmatic children classified into two groups of severity. The outcomes included incidence and prevalence of asthma attacks, symptoms and use of supplementary beta2-agonists, peak expiratory flow (PEF) value and its variability. The statistical analysis controlled the lack of independence between daily health outcomes, trends and meteorology. Air pollution was associated with an increase in reports and duration of asthma attacks and asthma-like symptoms in mild asthmatic children. The strongest association was the risk of asthma attack for an increase of 50 microg x m(-3) of sulphur dioxide (SO2) on the same day (odds ratio (OR)=2.86). Maximum reduction in morning peak expiratory flow (PEF) (5%) and maximum increase in PEF variability (2%) were observed at a lag of 3 days for an increase of 50 microg x m(-3) of SO2 in the subgroup of mild asthmatics receiving no regular inhaled medication. In moderate asthmatic children, the duration of supplementary beta2-agonist use was strongly associated with air pollution. The general pattern of our results provides evidence of the effect of the low levels of air pollution encountered in Western Europe on symptoms and lung function in childhood asthma.

Resume La tracheobronchomalacie primaire (TBM) est une maladie assez commune du jeune enfant secondaire a une insuffisance de maturation de cartilage tracheobronchique. Il faut evoquer ce diagnostic devant une toux tracheale caverneuse et un « wheezingchronique de survenue retardee apres la naissance (notamment a la suite d'une infection virale) et rebelle aux traitements anti asthmatiques. Des signes physiques refletant une atteinte anatomique des voies aeriennes hautes, notamment l'absence de distension et de signes de retraction sont evocateurs du diagnostic. L'examen clef pour le diagnostic est la fibroscopie bronchique souple sous anesthesie locale qui montre une fermeture excessive de la lumiere tracheale et/ou bronchique a l'expiration forcee ou lors des efforts de toux. Les TBM secondaires sont ecartees par l'anamese (prematurite, ventilation neonatale) un contexte polymalformatif (atresie de l'oesophage, entonnoir xyphoidien, dysmorphie faciale) et systematiquement par la realisation d'un oesophage baryte (pour les anomalies des arcs aortiques). La kinesitherapie respiratoire est le traitement de choix. L'antibiotherapie et les bronchodilatateurs (plutot de type atropinique de synthese) peuvent etre utiles. De facon tout a fait exceptionnelle, une chirurgie thoracique (a type de tracheoplexie, ou de prothese endobronchique) peut se discuter surtout dans les TBM secondaires et/ou dependantes de la ventilation assistee. L'evolution naturelle de la TBM vers la guerison survient grâce a la croissance de l'arbre tracheobronchique vers l'âge de 3 ans.

The current issues debate will bring together experts around the themes of self-sufficiency (in its national and European aspects) and of needs in cellular blood products. The point of view of the manufacturer and prescribers of blood products will be confronted.

Resume Les reactions anaphylactiques aux medicaments etaient exceptionnellement observees en pratique anesthesiologique pediatrique, avant 1990. La premiere reaction anaphylactique peroperatoire au latex a ete decrite chez l'enfant en 1989. Depuis cette date, l'incidence de telles reactions au latex s'est accrue en permanence, de meme que les reactions anaphylactiques aux myorelaxants. Dans un rapport de l'ADARPEF publie en 1993, les incidences ont ete chiffrees pour le latex et les myorelaxants respectivement a 75 et 10 p. cent. Le risque de developper de telles reactions doit etre essentiellement recherche par une enquete allergologique pre-operatoire, chez les enfants atopiques ou multi-operes.

Les atropiniques de synthese (AS) sont utilises depuis de nombreuses annees dans le traitement des bronchopathies chroniques obstructives (BPCO), notamment d'origine asthmatique. L'avenement de forme nebulisee accessible des le plus jeune âge mais aussi chez les patients gravement obstrues (ne pouvant realiser une inspiration controlee) permet aujourd'hui une utilisation plus large de ces produits chez l'enfant.

International audience; The French co-operative epidemiological study EGEA realised in 1991/95 combines a case control study and a study of the families of asthmatic cases. A synthesis of the results already obtained is presented. Smoking was related to IgE, even in asthmatics and was clearly related to the clinical severity of asthma, an aspect insufficiently taken into account. The relationships of occupational exposures to asthma have been assessed using a job exposure matrix. Segregation analyses on IgE have shown, after correction for the mode of ascertainment, the existence of a dominant major gene and familial residual correlation. A systematic genome screen realised in families with 2 asthmatic siblings showed linkage of various regions in the genome implicated to asthma or related phenotypes (1p, 11p, 11q, 12q, 13q, 17q, 19q), coherent with genome screens realised in other studies. Regarding candidate genes, no association was evidenced between asthma and the AF508 mutation of the cystic fibrosis gene. The analysis is still in progress by studies on the heterogeneity of asthma with refined genetic studies and by searching to integrate results regarding environmental and genetic factors and studying their interactions.

Resume L'allergie au cours de la mucoviscidose pose un probleme nosologique. Ainsi il faut distinguer plusieurs tableaux physiopathologiques lies a l'inflammation secondaire ou non a l'allergie. Les reactions immunologiques IgE et/ou IgG mediees a l'aspergillus, quasi constante au cours de l'evolution, precedent l'aspergillose bronchopulmonaire allergique (ABPA) qui touche 10 p. cent des enfants mucoviscidosiques. La sensibilisation aux pneumallergenes usuels, responsable d'asthme allergique, n'est pas plus frequente que dans la population generale. L'hyperreactivite bronchique (HRB) et les sibilances cliniques peuvent etre liees au stade evolutif de la mucoviscidose et sans relation avec l'allergie. L'inflammation constante au cours de la mucoviscidose peut preceder ou etre liee a l'infection chronique (d'origine bacterienne, mais aussi fungique, virale, ou a germes atypiques) plutot qu'a l'allergie. Pour le moment le seul traitement codifie de l'allergie au cours de la mucoviscidose est celui de l'ABPA, qui fait essentiellement appel aux corticoides. Dans l'avenir une meilleure comprehension des mecanismes impliques dans l'inflammation liee ou non a l'allergie devrait guider des traitements anti-inflammatoires plus cibles notamment sur l'expression des cytokines et leurs actions deleteres eventuelles sur la proteine CFTR.

This study was conducted by the AFLM in order to determine the performance characteristics of 12 commercially available nebulizers (6 ultrasonic and 6 jet) used in the treatment of cystic fibrosis (CF

International audience; BACKGROUND: The EGEA study combines a case-control study and a family study to assess genetic and environmental risk factors and their interactions for asthma, bronchial hyperresponsiveness and atopy. Information is scanty regarding potential selection biases, in particular regarding familial ressemblance in epidemiological surveys of this kind. METHODS: Asthmatic probands (adult and paediatric) were recruited in chest clinics of six clinical centres. Controls were mostly population-based (electoral rolls) for adults and recruited in surgery departments for children. RESULTS: The population examined includes 348 nuclear families ascertained by one asthmatic and 416 controls, totalling 1847 subjects (EGEA I) and an additional sample of 40 families ascertained by two asthmatic siblings (EGEA II). Potential biases for the various types of analyses have been studied. Quantification of the consequences of the greater participation of probands with a parental history of asthma shows it does not introduce a major bias in the estimates of familial resemblance. Cases and controls showed a good comparability regarding sex, age, area of residence and familial geographical origin, allowing proper associations studies for environmental and candidate genetic factors. CONCLUSIONS: The case-control component of the study will allow to perform studies on environmental factors and association studies for various genetic polymorphisms. Using the family base collected, segregation and genetic linkage/association analyses with DNA markers may be performed.

Resume Un accident survenu dans une meme ecole, chez deux enfants allergiques a l’arachide, permet de discuter le danger du soja chez l’allergique a l’arachide et la rarete des accidents reellement severes par allergie alimentaire a l’arachide. Ces observations appellent egalement des reflexions sur la faible information des personnels de cantine sur l’allergie alimentaire, le traitement des manifestations anaphylactiques, et les phenomenes psychogeniques collectifs.

Summary A 2-year-old male infant suffering from pulmonary alveolar proteinosis was treated by four unilateral bronchoalveolar lavages (BAL) in a 12-month period. The lavages were performed under general anaesthesia and controlled ventilation by introducing a fibrescope (3.6 mm external diameter) though either a tracheal tube (4.5 mm internal diameter) or a rigid bronchoscope. Each lobe of the lung was successively catheterized and the segments were washed separately with prewarmed saline solution injected through the side channel of the fibrescope. The described technique allows to perform BAL in safe conditions (i.e., controlled airways) in infants weighing more than 9 kg.

To evaluate the contribution of energy expenditure to the energy imbalance seen in cystic fibrosis patients, resting energy expenditure was measured using open-circuit indirect calorimetry in eight infants with cystic fibrosis, aged 2-7 months (mean, 4), without overt lung disease and in 10 healthy age-matched controls. In both groups, we found close, significant, linear correlations between resting energy expenditure and body weight and between resting energy expenditure and fat-free mass as measured by anthropometry. Cystic fibrosis patients had a 26% increase in resting energy expenditure per kilogram of fat-free mass as compared with controls and a 32% increase in resting energy expenditure as compared with predicted values for fat-free mass. These data from young infants free of clinical symptoms suggest a constitutional metabolic disorder in cystic fibrosis and support the need for early nutritional therapy in cystic fibrosis patients.

International audience

Persistent asthma in adults starts often early in childhood and is associated with alterations in respiratory function that occur early in life.The aim of this study was to evaluate the importance of innate and environmental factors associated with occurrence of asthma during childhood in a population of recurrent wheezing infants followed prospectively.A cohort of infants less than 30 months old with recurrent wheezing was established in order to assess severity of respiratory symptoms and to look for the presence of atopy and environmental risk factors. At the age of 6 years, they were reevaluated with respect to remission or persistence of wheezing over the previous 12-month period.Data were available for 219 subjects aged 15 +/- 5 months. In 27% of the infants with recurrent wheeze, wheezing persisted until the age of 6 years. In multivariate analysis, stepwise logit analysis showed that the risk factors for persistent wheezing are eosinophiliaor=470/mm(3), allergenic sensitization, and a father with asthma. Environmental factors present during the first year of life that protect from persistence of wheezing are ( 1 ) breastfeeding for longer than 3 months, ( 2 ) pets at home, and ( 3 )or=3 siblings. The detection rate for persistent wheezing in this model is 72%. The persistence score showed good specificity 91% but low sensitivity 35%.This study confirms the role of atopic host factors on wheezing persistence during childhood and detected protective environmental factors.

To cite this article: Laoudi Y, Nikasinovic L, Sahraoui F, Grimfeld A, Momas I, Just J. Passive smoking is a major determinant of exhaled nitric oxide levels in allergic asthmatic children. Allergy 2010; 65: 491–497. Abstract Background: Fraction of exhaled nitric oxide (FeNO) is considered, by some authors, to be a treatment follow-up parameter in allergic asthmatics. However, factors such as active smoking can influence NO production and must be taken into account in the interpretation of FeNO values. In children, the evidence in favour of an impact of passive smoking (PS) on FeNO values is controversial. The aim of this study was to evaluate the impact of chronic PS on FeNO in allergic asthmatic children. Methods: Seventy nontreated allergic asthmatic children over 5 years of age, exposed and unexposed to PS, underwent measurement of FeNO, spirometry, and allergic tests (skin prick tests, total and specific serum IgE, and blood eosinophilia). Children were considered to be exposed to PS when at least 1 cigarette per day was declared to be smoked at home. Results: Geometric mean FeNO value in 22 children exposed to PS was 26.3 ± 1.5 ppb vs 56.3 ± 1.7 ppb in 48 children unexposed (P

International audience

Summary Background Early wheezing in infants is a potential risk factor for persistence of asthma into adulthood. Moreover, a personal or familial history of atopy are risk factors associated with persistence of pre-existing wheezing during childhood. However, their relative importance remains unclear. Objectives Firstly to determine the critical thresholds of common biological markers of atopy in wheezy infants associated with persistence of wheezing into childhood and secondly to rank these biological markers together with clinical parameters according to the strength of their association with wheezing persistence. Methods A cohort of infants less than 30 months old with recurrent wheezing was established in order to assess severity of respiratory symptoms and to look for the presence of atopy. At the age of 6 years, they were re-evaluated regarding remission of wheezing over the previous 12-months period. Results Data were available for 219 subjects. In 27% of them, wheezing persisted at 6 years of age. Critical biological thresholds associated with the risk of wheezing persistence were: (1) a blood eosinophilia count 470/mm3 (defining eosinophilia), and (2) a total serum IgE level 45 IU/mL (defining elevated IgE) during infancy. A multiple component factorial analysis identified a dimension associating eosinophilia, elevated IgE and allergic sensitization on the one hand with persistent wheezing at 6 years of age on the other (λ=0.15). According to a segmentation analysis, the main discriminative parameter of wheezing persistence was eosinophilia. Thus a lack of eosinophilia alone could account for 91% of infants in remission, and when combined with absence of allergic sensitization, remission was correctly discriminated in 96.9% of the study population. Conclusion Our data strongly suggest that the lack of eosinophilia in wheezy infants without ongoing infection could predict future remission of wheezing in a large majority of cases.

International audience; The precautionary principle has been the subject of a heated debate in recent months in France, not least because it was mentioned in the Environmental Charter discussed by the French Parliament in 2005, and included in the French constitution. In this context, the French Committee for Prevention and Precaution has issued a position paper-presented hereafter-in order to remind legislators and the public of the essential rationale of the precautionary principle, as the committee conceives it. The Committee for Prevention and Precaution (CPP) is an advisory body to the French Ministry of the Environment (now Ministry of Ecology and Sustainable Development), which was created by a Ministerial Decree on 30 July 1996 with the aim of contributing to giving sound foundations to the Ministry's policies in matters related to risk prevention and precaution; detecting, and providing warning and expertise on health issues related to disruptions in the environment; and creating a linkage between scientific research and knowledge on one hand, and regulatory action on the other. Its operational resources are provided by the Ministry's Department of Economic Studies and Environmental Assessment. The CPP is comprised of 19 scientific experts from the field of health and environment, and chaired by Professor Alain Grimfeld.

The prevalence of asthma and allergic diseases has increased world-wide during the last quarter of the 20th century, particularly among children and adolescents. No change common to all sites where asthma has increased throughout the world has been identified, suggesting that this 'epidemic' phenomenon is likely due to multiple factors. The following have been most discussed: exposure to indoor and outdoor allergens, modification of the patterns of respiratory infections, decreasing trends of physical activity, evolution in the make-up of environmental irritants, including tobacco smoke and urban air toxicants. In this review, we point out the role of exposure to air pollutants, in addition to and in combination with other asthma enhancers or precipitators. Whereas concentrations of the 'classical' air quality indicators (SO2, CO) have more or less steadily decreased, asthma prevalence augmented in developed countries during the same period. However, the nature of the air pollution mix has deeply evolved, and should also be considered. Ambient air concentrations of industrial and house heating combustion sources of pollutants in the city have substantially decreased, but by contrast the concentrations of various ultrafine particles have increased. Now, there is in vitro and in vivo evidence that exposure to urban air particles, and particularly to diesel exhausts, elicits chronic oxidative stress and repeated inflammatory responses, so that they may enhance allergic inflammation and airway hyper-responsiveness. Several epidemiological studies suggested an association between traffic density close to places of children's residence and prevalence of respiratory symptoms, and more specifically of asthma or allergic rhinitis symptoms in them. Chronic exposure during infancy to traffic-related pollutants may accelerate or even provoke, among genetically sensitive subjects, disruption of the normal regulatory and repair processes eventually contributing to the increase of asthma incidence.

Objective: Subnormal hypothalamic-pituitary-adrenal (HPA) function and rare cases of adrenal crisis have been reported in asthmatic children treated with inhaled corticosteroids. We investigated subnormal HPA activity and followed up affected patients until recovery of normal HPA functions. Study Design: 100 children with persistent asthma underwent low-dose corticotropin testing, with the administration of 1 µg of 1–24 ACTH intravenously. Treatments were beclomethasone dipropionate as a metered-dose inhaler, n = 14, budesonide as a dry-powder inhaler, n = 16, fluticasone propionate as a metered-dose inhaler n = 31 or a dry-powder inhaler n = 39. The mean commercially labelled dose was 520 ± 29 µg/day (mean ± SEM, range: 160–1,000) and the equipotent dose (which compares the efficiency of these drugs for treating asthma and their responsibility for systemic effects) was 890 ± 55 µg/day (range: 200–2,000). Results: The mean stimulated cortisol level ± SEM (and range) of the patient was 482 ± 12 (148–801), and that of 40 age-matched controls was 580 ± 12.5 (439–726), (SD = 79). The result was subnormal (more than 2 SD below the mean of the controls) in28 of the 100 patients. One–four stepwise decreases of 10–100% in the daily equipotent doses received by the patients with abnormal low-dose corticotropin testing results led to normal results in subsequent low-dose corticotropin testing in 27 retested patients. The mean time interval between two tests was 5 months (range: 2–6 months) and the mean period required for normalization of the test was 13 months (range: 2–21). Only one case of asthma exacerbation and no adrenal crisis were observed over these periods. Conclusions: Decreasing daily equipotent doses led to recovery of normal HPA function without asthma exacerbation. Thus, a revision of the doses of inhaled corticosteroids used in asthmatic children with a progressive decrease to the consensus-recommended doses should decrease the systemic effects of inhaled corticosteroids, while minimizing the risk of asthma exacerbation.

Specific immunotherapy involves the administration of allergen extracts to achieve clinical tolerance of the allergens which cause symptoms in patients with allergic conditions. Immunotherapy has been shown to be effective in patients with mild forms of allergic diseases, specially in upper airway diseases. Recent studies suggest that specific immunotherapy may also modify the course of allergic disease, by reducing the risk of developing new allergic sensitizations, and also inhibiting the development of clinical asthma in children treated for allergic rhinitis. The traditional subcutaneous route is burdened with the risk of severe adverse events, therefore, local routes have been investigated and developed. The sublingual route is supported by numerous controlled trials showing its efficacy in rhinitis. The safety profile, assessed in clinical trials studies, is satisfactory. Several points still need to be elucidated, including mechanisms of action, optimal dosage, cost-effectiveness, and adherence. New approaches using mimic bacterial DNA vaccines alone or associated to modified allergen, which enhances immunogenicity in terms of eliciting a Th1-type response vaccines, are also undergoing serious consideration.

Lung scintigraphy provides a regional, functional test of pulmonary ventilation and perfusion. It allows an early detection of pulmonary damage or dysfonction, in particular in cystic fibrosis (CF) and other chronic obstructive pulmonary disease (COPD) in childhood.We report two cases in children suffering from CF and COPD (of undefined aetiology), who had a major localized ventilation disorder. They have been detected by lung scintigraphy before the development of clinical or radiological symptoms. An obstructive bronchial cast in the corresponding lobar bronchus was then revealed and withdrawn by bronchial fiberscopy.Lung scintigraphy allows early detection of local pulmonary abnormalities, sometimes undetectable with a chest X-ray or even with a chest tomodensitometry. It can reveal bronchial obstructive plugs, avoiding thus the development of bronchectasies thanks to a quick suitable treatment.

Summary Background Given the morbidity and mortality of asthma and the recent dramatic increase in its prevalence, pharmacologic prophylaxis of this disease in children at risk would represent a major medical advance. Objectives The Preventia I Study was designed to evaluate the efficacy and long-term safety of loratadine in reducing the number of respiratory infections in children at 24 months. A secondary objective was to investigate the benefit of loratadine treatment in preventing the onset of respiratory exacerbations. Methods Preventia I was a randomized placebo-controlled study involving 22 countries worldwide. The children were 12–30 months of age at enrolment and had experienced at least five episodes of ENT infections, and no more than two episodes of wheezing during the previous 12 months. Phase I was a 12-month double-blind period during which the children were treated with loratadine 5 mg/day (2.5 mg/day for children24 months of age) or placebo. Phase II was a double-blind follow-up period without study medication. Results Of the 412 children enrolled, 342 and 310 completed Phase I and Phase II, respectively. The results showed a significant decrease in the number of infections in the whole population of children. However, no difference was observed between the loratadine and placebo group. When considering secondary end-points, loratadine was shown to reduce the number of respiratory exacerbations during the treatment phase. None of the 204 children who received loratadine discontinued the study because of drug-related events. Loratadine treatment was not more sedative than placebo and was not associated with cardiovascular events. Conclusion The strong decrease in the rate of infections in the children at risk of recurrent infections, while not being influenced by loratadine treatment, should encourage future reflection in terms of prophylactic management. This study also confirms the long-term safety of loratadine and its metabolites in young children.

Summary The role of rapidly growing mycobacteria (RGM) in pulmonary disease is unclear. We report one case of lung disease caused by RGM in a 6-year-old child with cystic fibrosis. Mycobacterium chelonae was identified and was susceptible only to kanamycin and clarithromycin. The child, who clinically improved with clarithromycin, received treatment for 12 months and negativity of cultures was obtained. Diagnosis of lung disease caused by RGM is based on microbiologic, histologic, radiographic and clinical criteria. The majority of cases are caused by Mycobacterium chelonae abscessus . This organism is uniformly resistant to standard antituberculosis drugs and many other antibiotics, but clarithromycin has excellent activity against it; clinical trials of this newer macrolide are ongoing to evaluate the role of this agent for treatment of M. chelonae abscessus lung disease.

To evaluate the relationship between clinical parameters and differential cell counts, bronchoalveolar lavage was performed in 79 asthmatic infants and children with unusual asthma. Multivariate analysis showed significant associations between (1) allergic asthma and the presence of alveolar eosinophils and (2) persistent and longer asthma and an increased number of alveolar neutrophils. Our results provide the first evidence that in asthmatic infants and children eosinophilic inflammation is related to allergic sensitization.

Les manifestations allergiques, l’asthme en particulier, sont de plus en plusfréquentes dans tous les pays industrialisés. Il faut également remarquer quenon seulement la prévalence mais aussi la sévérité de l’asthme se sont fortementaccrues au cours des dernières années. Plusieurs études effectuées àtravers le monde montrent que, depuis 1960, la fréquence de l’asthme s’accroîtd’environ 6 % à 10 % par an chez l’enfant, quels que soient le pays ou l’ethnieétudiés. Elle est la première maladie chronique de l’enfant dans les paysdéveloppés. Cette augmentation ne semble pas procéder d’une modificationdes moyens de diagnostic ou d’une meilleure connaissance de l’affection.Si la prise en charge de l’asthme a nettement progressé depuis une vingtained’années, du fait d’une meilleure connaissance des mécanismes physiopathologiquesde la maladie et de l’arrivée sur le marché de nouvelles thérapeutiques,il reste cependant essentiel d’appréhender les facteurs à l’origine de saprogression foudroyante.Les facteurs à l’origine des maladies allergiques, et de l’asthme en particulier,sont de deux ordres, génétiques et environnementaux, d’importantes interactionsexistant entre eux. Si un certain nombre de gènes candidats pourl’immunopathologie de l’asthme sont en cours d’identification, des modificationsde ces gènes ne peuvent constituer une explication cohérente pourrendre compte de l’augmentation de la prévalence de l’asthme observée cesvingt dernières années. Les facteurs environnementaux apparaissent commel’explication la plus plausible : la pollution de l’air et les modifications dumode de vie, d’une part, la disparition de facteurs de résistance (infections aucours de la petite enfance), d’autre part, sont en première ligne des responsablespossibles.L’asthme est défini comme une obstruction bronchique réversible, spontanémentou sous l’effet de traitements bronchodilatateurs. Sur le plan physiopathologique,l’asthme est caractérisé par une inflammation de la muqueusebronchique. Cette inflammation est constante, plus ou moins importanteselon le stade de gravité de la maladie.La prise en charge des asthmatiques a largement bénéficié d’une meilleurecompréhension des mécanismes physiopathologiques impliqués dans le développementde la maladie. Cette meilleure connaissance a permis d’élaborerune stratégie thérapeutique cohérente et de proposer des schémas de traitementsappropriés aux différentes formes d’asthme.Cependant, si nous avons largement progressé dans la compréhension del’histoire naturelle et la prise en charge de l’asthme, il n’existe pas encore de traitement curateur de la maladie. C’est dire l’importance des mesures préventives,qui reposent avant tout sur l’éducation des patients, mais aussi desmédecins. La prévention primaire implique un processus dans lequel l’interventionprécède le développement de la maladie. La prévention secondaire apour objectif de prévenir le développement de la maladie chez un sujetprédisposé, par exemple atopique. Pour les patients chez qui le diagnosticd’asthme a été posé, la prévention tertiaire consiste en une modification del’environnement et la prescription d’un traitement pharmacologique adapté.Ce document constitue une bonne synthèse des travaux les plus représentatifsen épidémiologie, physiopathologie et clinique. Il indique les principalesrecommandations en prévention et éducation à la santé, à l’intention desdifférents acteurs impliqués dans la prise en charge de cette pathologie, etpropose quelques pistes de recherche qui mériteraient d’être développées.