[Management of acute asthma in infants and children: recommendations from the French Pediatric Society of Pneumology and Allergy]

Digital Action Plan (Web App) for Managing Asthma Exacerbations: Randomized Controlled Trial

BACKGROUND

A written action plan (WAP) for managing asthma exacerbations is recommended.

OBJECTIVE

We aimed to compare the effect on unscheduled medical contacts (UMCs) of a digital action plan (DAP) accessed via a smartphone web app combined with a WAP on paper versus that of the same WAP alone.

METHODS

This randomized, unblinded, multicenter (offline recruitment in private offices and public hospitals), and parallel-group trial included children (aged 6-12 years) or adults (aged 18-60 years) with asthma who had experienced at least 1 severe exacerbation in the previous year. They were randomized to a WAP or DAP+WAP group in a 1:1 ratio. The DAP (fully automated) provided treatment advice according to the severity and previous pharmacotherapy of the exacerbation. The DAP was an algorithm that recorded 3 to 9 clinical descriptors. In the app, the participant first assessed the severity of their current symptoms on a 10-point scale and then entered the symptom descriptors. Before the trial, the wordings and ordering of these descriptors were validated by 50 parents of children with asthma and 50 adults with asthma; the app was not modified during the trial. Participants were interviewed at 3, 6, 9, and 12 months to record exacerbations, UMCs, and WAP and DAP use, including the subjective evaluation (availability and usefulness) of the action plans, by a research nurse.

RESULTS

Overall, 280 participants were randomized, of whom 33 (11.8%) were excluded because of the absence of follow-up data after randomization, leaving 247 (88.2%) participants (children: n=93, 37.7%; adults: n=154, 62.3%). The WAP group had 49.8% (123/247) of participants (children: n=45, 36.6%; mean age 8.3, SD 2.0 years; adults: n=78, 63.4%; mean age 36.3, SD 12.7 years), and the DAP+WAP group had 50.2% (124/247) of participants (children: n=48, 38.7%; mean age 9.0, SD 1.9 years; adults: n=76, 61.3%; mean age 34.5, SD 11.3 years). Overall, the annual severe exacerbation rate was 0.53 and not different between the 2 groups of participants. The mean number of UMCs per year was 0.31 (SD 0.62) in the WAP group and 0.37 (SD 0.82) in the DAP+WAP group (mean difference 0.06, 95% CI -0.12 to 0.24; P=.82). Use per patient with at least 1 moderate or severe exacerbation was higher for the WAP (33/65, 51% vs 15/63, 24% for the DAP; P=.002). Thus, participants were more likely to use the WAP than the DAP despite the nonsignificant difference between the action plans in the subjective evaluation. Median symptom severity of the self-evaluated exacerbation was 4 out of 10 and not significantly different from the symptom severity assessed by the app.

CONCLUSIONS

The DAP was used less often than the WAP and did not decrease the number of UMCs compared with the WAP alone.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02869958; https://clinicaltrials.gov/ct2/show/NCT02869958.

Fixed versus variable practice for teaching medical students the management of pediatric asthma exacerbations using simulation

Simulation-based trainings represent an interesting approach to teach medical students the management of pediatric asthma exacerbations (PAEs). In this study, we compared two pedagogical approaches, training students once on three different scenarios of PAEs versus training students three times on the same scenario of PAE. Eighty-five third-year medical students, novice learners for the management of PAEs, were randomized and trained. Students were assessed twice, 1 week and 4 months after the training, on a scenario of PAE new to both groups and on scenarios used during the training. The main outcome was the performance score on the new scenario of PAE at 1 week, assessed on a checklist custom-designed for the study. All students progressed rapidly and acquired excellent skills. One week after the training, there was no difference between the two groups on all the scenarios tested, including the new scenario of PAE (median performance score (IQR) of 8.3 (7.4-10.0) in the variation group versus 8.0 (6.0-10.0) in the repetition group (p = 0.16)). Four months later, the performance of the two groups remained similar.

CONCLUSION

Varying practice with different scenarios was equivalent to repetitive practice on the same scenario for novice learners, with both methods leading to transfer and long-term retention of the skills acquired during the training. What is known: • Simulation-based trainings represent an interesting approach to teach medical students the management of pediatric asthma exacerbations. • It is unclear whether students would benefit more from repetitive practice on the same scenario of asthma exacerbation or from practice on different scenarios in terms of transfer of skills. What is new: • An individual 30-min training on the management of pediatric asthma exacerbations using simulation allows transfer and long-term retention of the skills acquired. • Varying practice with different scenarios is equivalent to repetitive practice on the same scenario in terms of transfer of skills.

[Digital action plan for asthma exacerbations (PANAME)]

BACKGROUND

A written action plan (WAP) reduces emergency visits for asthma exacerbations. However, a WAP is underused and often focused on asthma control. The innovation is an AppWeb that includes an expert software aimed at diagnosing the level of severity of asthma exacerbations and delivering a personalized digital action plan (DAP) when patients are in urgent need of medical advice. Symptoms describing the level of severity of asthma exacerbations and the consequent treatments have been established by working groups of the French Respiratory Societies (SPLF and SP2A for adults and children, respectively). The main objective of the study is to evaluate the effect of the DAP on the frequency of urgent medical attendance. Secondary objectives are to evaluate adherence to the DAP compared to a WAP and the qualitative satisfaction of patients using the DAP.

METHODOLOGY

A randomized, prospective, comparative, multicenter study on two parallel groups, conducted in private practice and in hospitals. In both arms, asthmatic patients (240 children aged 6 to 12 years and 270 adults aged 18 to 50 years) with severe asthma exacerbation(s) during the previous year and an Internet connection via a smartphone or a tablet computer, will have at their disposal a WAP and one arm will have, in addition, the DAP. Included patients will be followed up every three months for one year.

EXPECTED RESULTS

A decrease in the number of urgent medical attendances and better adherence in the WAP+DAP group compared to the WAP group.

Nasal high flow in management of children with status asthmaticus: a retrospective observational study

Background

Asthma is the most common obstructive airway disease in children and adults. Nasal high flow (NHF) is a recent device that is now used as a primary support for respiratory distress. Several studies have reported use of NHF as a respiratory support in status asthmaticus; however, there are no data to recommend such practice. We therefore conducted this preliminary study to evaluate NHF therapy for children with status asthmaticus admitted to our PICU in order to prepare a multicentre randomized controlled study.

Results

Between November 2009 and January 2014, 73 patients with status asthmaticus were admitted to the PICU, of whom 39 (53%) were treated with NHF and among these 10 (26%) presented severe acidosis at admission (pH < 7.30). Thirty-four less severe children (41%) were treated with standard oxygen. For one child (2.6%) NHF failed and was then switched to non-invasive ventilation. NHF was discontinued in another patient because of the occurrence of pneumothorax after 31 h with NHF; the patient was then switched to standard oxygen therapy. Mean ± SD heart rate (165 ± 21 vs. 141 ± 25/min, p < 0.01) and respiratory rate (40 ± 13 vs. 31 ± 8/min, p < 0.01) decreased significantly, and blood gas improved in the first 24 h. In the subgroup of patients with acidosis, median [IQR] pH increased significantly between hour 0 and 2 (7.25 [7.21–7.26] vs. 7.30 [7.27–7.33], p = 0.009) and median [IQR] pCO₂ decreased significantly (7.27 kPa [6.84–7.91 vs. 5.85 kPa [5.56–6.11], p = 0.007). No patient was intubated.

Conclusion

This retrospective study showed the feasibility and safety of NHF in children with severe asthma. Blood gas and clinical parameters were significantly improved during the first 24 h. NHF failed in only two patients, and none required invasive ventilation.

Epidemiological and clinical characteristics of patients infected with enterovirus D68, France, July to December 2014

In 2014, the United States (US) experienced a nationwide outbreak of enterovirus D68 (EV-D68) infection with 1,152 cases reported mainly in hospitalised children with severe asthma or bronchiolitis. Following the US alert, 11 laboratories of the French enterovirus (EV) surveillance network participated in an EV-D68 survey. A total of 6,229 respiratory samples, collected from 1 July to 31 December 2014, were screened for EV-D68 resulting in 212 EV-D68-positive samples. These 212 samples corresponded to 200 EV-D68 cases. The overall EV-D68 positivity rates among respiratory samples were of 5% (184/3,645) and 1.1% (28/2,584) in hospitalised children and adults respectively. The maximum weekly EV-D68 positivity rates were of 16.1% for children (n = 24/149; week 43) and 2.6% for adults (n = 3/115; week 42). Of 173 children with EV-D68 infection alone, the main symptoms were asthma (n = 83; 48.0%) and bronchiolitis (n = 37; 21.4%). One child developed acute flaccid paralysis (AFP) following EV-D68-associated pneumonia. Although there was no significant increase in severe respiratory tract infections reported to the French public health authorities, 10.7% (19/177) of the EV-D68 infected children and 14.3% (3/21) of the EV-D68 infected adults were hospitalised in intensive care units. Phylogenetic analysis of the viral protein 1 (VP1) sequences of 179 EV-D68 cases, revealed that 117 sequences (65.4%), including that of the case of AFP, belonged to the B2 variant of clade B viruses. Continuous surveillance of EV-D68 infections is warranted and could benefit from existing influenza-like illness and EV surveillance networks.

Impact of a short early therapeutic education program on the quality of life of asthmatic children and their families

OBJECTIVES

Few studies have been made on the impact of therapeutic education (TE) on the quality of life (QOL) of asthmatic primary-school aged children. We attempted to assess the beneficial effects on the QOL of children and their parents of a short TE program initiated immediately after the first consultation with a pediatric pulmonologist.

METHODS

The QOL of 31 families of asthmatic children (aged 5-11) was measured before and 3 months after a short and early programme of TE by the French version of the Pictured Child's Quality of Life Self Questionnaire (AUQUEI, AUtoquestionnaire QUalité de vie Enfant Imagé) for the children, and by the Paediatric Asthma Caregiver's Quality of Life Questionnaire (PACQLQ) for the parents. The other criteria studied were asthma management, school and workplace absenteeism and functional respiratory parameters.

RESULTS

TE did not significantly alter the AUQUEI score (P = 0.67). No change was observed in the different areas studied: autonomy (P = 0.97), leisure activities (P = 0.64), functions (P = 0.88), and social relations (P = 0.51). In contrast, the PACQLQ score considerably improved after TE (P < 0.001), as evidenced by reduced activity limitations (P < 0.001) and improved emotional functioning of parents (P < 0.001). These results were accompanied by a significant improvement in asthma management, with, in particular, a major decrease in the use of medication (P < 0.001) and the number of unscheduled medical consultations (P < 0.001) and visits to the emergency department (P = 0.02); a decrease in school absenteeism (P = 0.009); and an improvement in forced expiratory volume in 1 sec (FEV₁ ) (P = 0.05).

CONCLUSIONS

Our TE program had rapid and beneficial effects on numerous objective and subjective parameters, thereby contributing to the well-being of the families and probably to a subsequent decrease in the overall cost of asthma management. Pediatr Pulmonol. 2015; 50:213-221. © 2014 Wiley Periodicals, Inc.

[Epidemiological profile and management of asthma exacerbations in children at the Rabat Children Hospital in Morocco]

Introduction

Méthodes

Résultats

Conclusion

[Value of routine identification of respiratory infectious agents in children hospitalized with an acute asthma exacerbation]

Introduction

Chez l’enfant les exacerbations d’asthme sont le plus souvent déclenchées par une infection respiratoire. L’objectif de cette étude était d’évaluer l’intérêt de l’identification des pathogènes respiratoires chez les enfants hospitalisés pour une exacerbation d’asthme.

Patients et méthodes

Il s’agit d’une étude rétrospective incluant tout enfant hospitalisé pour une exacerbation d’asthme dans notre unité entre janvier 2010 et décembre 2011 et analysant la prescription des examens microbiologiques, leurs indications, leur rendement, leur impact sur la prise en charge médicale et leur coût.

Résultats

Cent quatre-vingt-dix-sept enfants ont été inclus. Une recherche d’agent pathogène respiratoire avait été réalisée chez 157 enfants (79,7 %), surtout en cas d’infection oto-rhino-laryngologique (ORL), d’hypoxémie ou de pneumonie. Un virus avait été identifié chez 30 (23,8 %) des 126 enfants prélevés. Les analyses bactériologiques avaient eu un rendement faible puisque seulement 3,2 % des analyses par amplification génique (PCR) pour Mycoplasma pneumoniae avaient été positives (n = 4/125). Aucune autre bactérie n’avait été identifiée. Aucun lien n’a pu être établi entre les résultats microbiologiques et la gravité de l’exacerbation. La prise en charge thérapeutique avait été peu modifiée par ces résultats. Le coût global avait été de plus de 40 400 euros pour les 2 ans d’étude.

Conclusion

D’après nos résultats la recherche de pathogènes respiratoires au cours des exacerbations d’asthme a un intérêt modéré en dehors de l’aspect épidémiologique. L’impact du rhinovirus, du coronavirus, du bocavirus et de l’entérovirus, non recherchés en routine hospitalière, reste cependant à préciser.

[Update on the management of acute viral bronchiolitis: proposed guidelines of Grand Ouest University Hospitals]

BACKGROUND AND OBJECTIVES

While our European and North American colleagues have recently updated their recommendations, the 2000 Consensus Conference remains the main guideline on management of acute viral bronchiolitis in France. We aimed to establish an updated inter-regional protocol on management of acute viral bronchiolitis in infants.

METHOD

Pediatricians, pediatric pulmonologists, and emergency physicians of the Grand Ouest University Hospitals (France) gathered to analyze the recent data from the literature.

RESULTS

Criteria to distinguish childhood asthma from acute viral bronchiolitis were established, then prescriptions of diagnostic tests, antibiotics, and chest physiotherapy were defined and reserved for very limited situations. Similarly, the modalities of oxygen therapy prescription and nutritional support were proposed. Finally, other therapeutics such as nebulized hypertonic saline seem promising, but their place in the treatment of acute bronchiolitis in infants remains unclear.

CONCLUSION

This work has provided new proposals for management of acute viral bronchiolitis and helped standardize practices within the Grand Ouest University Hospitals. This local organization could lay the keystone for working toward guidelines initiated by learned societies at the national level.

Fraction of exhaled nitric oxide (FeNO ) norms in healthy North African children 5-16 years old

AIMS

(i) To identify factors that influence the FeNO values in healthy North African, Arab children aged 6-16 years; (ii) to test the applicability and reliability of the previously published FeNO norms; and (iii) if needed, to establish FeNO norms in this population, and to prospectively assess its reliability.

POPULATION AND METHODS

This was a cross-sectional analytical study. A convenience sample of healthy Tunisian children, aged 6-16 years was recruited. First subjects have responded to two questionnaires, and then FeNO levels were measured by an online method with electrochemical analyzer (Medisoft, Sorinnes [Dinant], Belgium). Anthropometric and spirometric data were collected. Simple and a multiple linear regressions were determined. The 95% confidence interval (95% CI) and upper limit of normal (ULN) were defined.

RESULTS

Two hundred eleven children (107 boys) were retained. Anthropometric data, gender, socioeconomic level, obesity or puberty status, and sports activity were not independent influencing variables. Total sample FeNO data appeared to be influenced only by maximum mid expiratory flow (l sec(-1) ; r(2)  = 0.0236, P = 0.0516). For boys, only 1st second forced expiratory volume (l) explains a slight (r(2)  = 0.0451) but significant FeNO variability (P = 0.0281). For girls, FeNO was not significantly correlated with any children determined data. For North African/Arab children, FeNO values were significantly lower than in other populations and the available published FeNO norms did not reliably predict FeNO in our population. The mean ± SD (95% CI ULN, minimum-maximum) of FeNO (ppb) for the total sample was 5.0 ± 2.9 (5.4, 1.0-17.0). For North African, Arab children of any age, any FeNO value greater than 17.0 ppb may be considered abnormal. Finally, in an additional group of children prospectively assessed, we found no child with a FeNO higher than 17.0 ppb.

CONCLUSION

Our FeNO norms enrich the global repository of FeNO norms the pediatrician can use to choose the most appropriate norms based on children's location or ethnicity.

[Inhaled medication in pediatrics]

Three different devices are available for inhaled medications in children: the pressurized metered dose inhalers (pMDIs, breath-actuator synchronized pMDI, and valved holding spacers), the dry powder inhalers, and the nebulizers. To choose the better device for a particular patient, a perfect knowledge of the available devices, of their mode of use, of their advantages and inconvenient is required. The use of a pMDI coupled to a valved holding spacer is the first mode of delivery to propose in children aged less than 6 years. After 6 years old, the DPIs may be proposed depending on the child's competences. At last, the nebulizations are indicated in some particular and severe indications, but new indications are appearing because of recent progresses.

[Admissions for pediatric asthma in France]

INTRODUCTION

Most hospital admissions for asthma exacerbation are avoidable with adequate disease management. The objective of this study was to describe admissions for asthma in children in France using data from the French nationwide hospital database.

METHODS

We selected admissions having either a main diagnosis of asthma or a main diagnosis of acute respiratory failure (ARF) with asthma as an associated diagnosis, occurring in children (age<15years) between 2002 and 2010 in France (excluding French Guyana).

RESULTS

In 2010, 35,004 asthma admissions and 1381 cases of asthma-related ARF were recorded (crude admission rate, 30.1/10,000 children); the mean length of stay was 2days. The in-hospital lethality rate ranged from 0.01% to 0.03% depending on the year. The annual age-standardized admission rate increased between 2002 and 2010 (+2.5% per year on average in metropolitan France). In 2010, 11.8% of children admitted for asthma or asthma-related ARF were readmitted for asthma or asthma-related ARF at least once within the same calendar year, and 1.3% were readmitted within the week following admission. The proportion of children aged less than 5 years who were readmitted within the same calendar year increased between 2002 and 2010.

CONCLUSION

The increase in admission and readmission rates indicates non-optimal management of asthma in children in France.

[Characteristics of admissions to pediatric emergency departments for exacerbations of asthma. Assessment and prospects for improving prehospital care]

INTRODUCTION

The frequency of emergency department visits for asthma is a major public health problem in pediatrics. The aim of this study is to establish the characteristics of children visiting pediatric emergency departments for acute asthma and to assess their therapeutic management prior to admission.

METHODS

A prospective clinical study performed during 3 months at the pediatric emergency department of the university teaching hospital of Clermont-Ferrand, of children aged 1 to 16 years admitted to the department with a clinical diagnosis of asthma exacerbation.

RESULTS

One hundred and forty-three patients were included in the study. Asthma crises were moderate to severe in 69.2% of cases (n=99). Initial therapeutic management prior to the admission to the emergency department was appropriate in 17.5% of cases (n=25). Most of the known asthmatic patients had not been followed up by a pediatric pulmonologist (n=56). A crisis protocol had been set up in 16.5% of cases (n=20). Exacerbations were more severe among younger patients (P=0.002) and economically disadvantaged children (P=0.025).

CONCLUSIONS

This study uncovers poor knowledge of the disease among asthmatic children and their families, and an insufficient awareness among health practitioners of current recommendations for the treatment of asthmatic children. Admissions to the emergency department for asthma could be partly avoided by improving diagnosis and therapeutic education.

[Steroid intake before leukemia diagnosis impairs outcome in childhood acute lymphoblastic leukemia]

The aim of this study was to show that steroid therapy taken before the diagnosis of acute lymphoblastic leukemia (ALL) can alter the management of the disease.

PATIENTS AND METHODS

We conducted a multicenter retrospective study on 11 children treated between 2005 and 2011, who received oral steroids ranging from 0.6 to 3.3mg/kg/day prednisolone equivalent for a duration of 2 to 15 days during the 2 months prior to diagnosis of ALL.

RESULTS

Four children had febrile pancytopenia. Among them, 2 had severe infections and a noncontributive bone marrow aspiration. One of them presented a severe tumoral lysis syndrome and was hospitalized twice in the intensive care unit. Two teenagers had central nervous system involvement at diagnosis of T-ALL, 1 having associated cutaneous locations, the second one showing pulmonary and central nervous system (CNS) leukostasis with renal failure and disseminated intravascular coagulation. One child died of septic shock during the induction phase of steroid-resistant T-ALL. Four children had no complications during the induction phase. Steroid resistance occurred in 5 cases and steroid sensitivity could not be evaluated in 3 cases. Three allogeneic bone marrow transplants were performed: the first one because of early CNS relapse, the 2 others because of initial treatment resistance.

CONCLUSION

Steroids can induce a delay in the management of ALL and seem to favor initial complications, and possibly increase diffuse locations as well as steroid resistance. Their prescription needs to be carefully managed, especially for uncharacteristic infectious symptoms. Then a complete blood count should be done.

[Mild asthma in children: new data and a revival of interest]

According to the Global Initiative for Asthma (GINA) classification, mild asthma includes intermittent and mild persistent asthma. It represents more than 75% of asthmatic children. The symptoms and functional impact are well described. Mild asthma can lead to severe exacerbations. Progression to more severe disease may occur. Consequently, it is important to diagnose mild asthma, to initiate the appropriate treatment early, and to identify the risk factors for aggravation. Nevertheless, mild asthma is under-diagnosed and under-treated. Bronchial inflammation and remodeling are observed in mild asthma. A daily low-dose of inhaled corticosteroids is the reference treatment for mild persistent asthma. Intermittent inhaled corticosteroids cannot be recommended in children with mild persistent asthma.

[Asthma: treatment of exacerbations]

INTRODUCTION

Exacerbations remain, in both adults and children, a common reason for emergency consultation. The management of the asthmatic patient with an acute exacerbation is well defined.

BACKGROUND

The initial evaluation, based on the background risk factors and the clinical examination, will determine the choice of treatment and management. Treatment is based on bronchodilators and corticosteroids in the majority of cases.

VIEWPOINTS

An episode of exacerbation may be the opportunity to establish contact with the patient (an educational approach) to improve the adherence to long-term treatment with inhaled corticosteroids, which remain the best way of preventing future exacerbations.

CONCLUSION

Early and appropriate management of exacerbations of asthma should reduce asthma morbidity and mortality. It could also reduce the socioeconomic costs of these episodes and the number and duration of hospital admissions.

[Asthmatic exacerbations: specific features in children]

L’asthme aurait déjà concerné plus de 10 % des enfants âgés de dix ans. Ce constat mérite une discussion pneumopédiatrique à part entière. Malgré des similitudes entre l’asthme de l’adulte et celui de l’enfant, la population pédiatrique présente certaines spécificités notamment concernant les exacerbations. L’asthme du nourrisson est une entité particulière dont la définition a bénéficié récemment d’une mise à jour officielle. Les étiologies d’exacerbations asthmatiques restent les infections, avec en tête les virus dont le typage joue un rôle pronostique. L’environnement intérieur et extérieur peut aggraver l’asthme, notamment par de fortes concentrations de polluants atmosphériques. Les nutriments semblent jouer un rôle pronostique par le biais de la vitamine D ou de la présence d’allergie alimentaire. La recherche de facteurs prédictifs ou de marqueurs inflammatoires de l’asthme est la clé de voûte pour la maîtrise de ces exacerbations, mais les techniques actuelles ne sont pas encore totalement performantes comme la mesure de l’oxyde nitrique exhalé (eNO), l’étude des crachats/exhalas ou encore de simples questionnaires. La prise en charge précoce et continue avec l’éducation thérapeutique des enfants et de leur famille demeure un outil efficace en termes de prévention de rechute des exacerbations.

[Adult asthma exacerbations in questions]

In this article a French working party critically review the international literature to revise the definition, pathophysiology, treatment and cost of exacerbations of adult asthma. The various guidelines do not always provide a consistent definition of exacerbations of asthma. An exacerbation can be defined as deterioration of clinical and/or functional parameters lasting more than 24 hours, without return to baseline, requiring a change of treatment. No single clinical or functional criterion can be used as an early marker of an exacerbation. Innate and acquired immune mechanisms, modified by contact with infectious, irritant or allergenic agents, participate in the pathogenesis of exacerbations, which are accompanied by bronchial inflammation. In 2010, mortality is related to progression of exacerbations, often occurring before the patient seeks medical attention. The objective of treatment is to control asthma and prevent exacerbations. However, many factors can trigger exacerbations and often cannot be controlled. The efficacy of inhaled corticosteroids has been demonstrated on reduction of the number of exacerbations and the number of asthma-related deaths. This treatment is cost-effective, especially in terms of reduction of exacerbations.

Asma infantil y del lactante

El asma es la enfermedad crónica más frecuente de la infancia. El diagnóstico suele ser fácil cuando se producen episodios de disnea espiratoria con sibilancias reversibles de forma espontánea o mediante el uso de broncodilatadores. Las radiografías de tórax, la exploración funcional respiratoria y el estudio alérgico constituyen el aspecto fundamental de las pruebas complementarias necesarias. El tratamiento de la crisis consiste en el uso de β2-adrenérgicos inhalados y, si es necesario, corticoides orales. El tratamiento de fondo tiene como objetivo limitar al máximo los síntomas y restaurar o mantener las funciones pulmonares normales. Se debe adaptar a la gravedad y al control de la enfermedad y los corticoides inhalados tienen un papel de elección.

[Exacerbation in asthma: definitions and immunopathology]

There is no unequivocal definition of exacerbation in asthma. These are defined as episodes of increased or aggravated respiratory symptoms or as use of oral corticosteroid therapy. Viral infection is the most frequent cause of exacerbations. Inflammation during exacerbations is heterogeneous. It may be associated with bronchial hypereosinophilia, which is used as a predictive marker for exacerbation, and with neutrophilia, which is more resistant to corticosteroids. During viral infection, an inappropriate Th1 antiviral inflammation develops, associated with the intrinsic Th2 activity that leads to an aberrant immune response. Exacerbations secondary to allergen exposure are classically described as due to a Th2-type inflammation; but Th1 response also seems to play a role. Exposure to air pollutants appears able not only to induce bronchial inflammation but also to potentiate the inflammatory reactions of patients with exacerbations.