Bronchial hyperreactivity to methacholine in atopic versus nonatopic asthmatic schoolchildren and preschoolers.

BACKGROUND: Atopy and bronchial hyperreactivity are factors related to severe and unremitting asthma of childhood; however, the prevalence of these factors could be different according to age of the child. OBJECTIVE: To determine if methacholine bronchial hyperreactivity (BHR) differs between atopic and nonatopic preschoolers and schoolchildren with mild-moderate asthma. METHODS: Data obtained from 340 children with diagnosis of asthma or recurrent wheezing, matched by atopic conditions (positive or negative skin prick test) and age, and who underwent a methacholine bronchial challenge test (by spirometry in schoolchildren and by transcutaneous oxygen pressure [TcP(O2)] in preschoolers) were reviewed. RESULTS: Among 136 schoolchildren (9.07 ± 2.5 years), the prevalence of positive BHR was significantly higher among atopics than nonatopics (75% versus 48.5%, p = .001, respectively), even after controlling for gender and nutritional status (adjusted odds ratio [aOR] = 3.2129, 95% confidence interval [CI]: 1.5-6.8; p = .002). In addition, atopic schoolchildren had lower PC(20) and required a lower threshold dose of methacholine to induce a reaction (0.53 versus 0.82 mg/ml, p = .055 and .5 versus 1 mg/ml, p = .02, respectively) than nonatopics. Nevertheless, basal and predicted forced expiratory volume in one second (FEV1) were similar between groups. In contrast, among 204 preschoolers (4.74 ± 1.1 years), there were no differences in the prevalence of positive BHR between atopics and nonatopics (74.5% versus 72.5%, p = .75, respectively). Furthermore, basal TcP(O2), a higher fall of TcP(O2) and lower threshold doses of methacholine required for induction as measured by TcP(O2) were similar between the atopic and nonatopic preschoolers. CONCLUSIONS: Atopic asthmatic schoolchildren have greater hyperresponsiveness to methacholine than nonatopics (only among those with normal nutritional status). However, atopic and nonatopic asthmatic preschoolers have similar hyperresponsiveness to methacholine. Therefore, factors different from atopy may be responsible for wheeze in younger children.

Neumonía complicada por Streptococcus pyogene, en una preescolar previamente sana / Pneumonia caused by Streptococcus pyogenes in a pre-school children

La neumonía es una causa frecuente de mortalidad en niños. El streptococcus pyogenes (Sp) es un agente etiológico poco frecuente de neumonía adquirida en la comunidad, pero puede producir infecciones invasoras severas rápidamente progresivas. En las últimas décadas se ha descrito un aumento en la incidencia de infecciones invasoras por Sp en la población general. Dentro de éstas la neumonía ocupa el tercer lugar en frecuencia. La presentación clínica de la neumonía por Sp es similar a la neumonía neumocócica, con inicio abrupto de fiebre, tos productiva y calofríos. Su diagnóstico y tratamiento adecuado son importantes para prevenir complicaciones secundarias como el síndrome de shock tóxico. En el presente artículo se describe el caso clínico de un preescolar de 4 años con una neumonía complicada por Sp y se revisa la literatura con respecto al diagnóstico y tratamiento.

[10-year experience in flexible bronchoscopy in pediatric patients]. / Experiencia en 10 años de aplicación de fibrobroncoscopia en pacientes pediátricos.

BACKGROUND: Approximately a decade ago, pediatric Flexible Bronchoscopy (FB) was introduced in Chile, after being used for several years in adults. AIM: To describe our clinical experience in FB in a ten years period. PATIENTS AND METHODS: Records of procedures done between January 1993 and September 2002 at the Pediatric Service of the Catholic University Hospital, were retrospectively reviewed. We evaluated the clinical indications for the procedures in relation to patient's age and the correlation between indications and FB findings. RESULTS: A total of 700 procedures were performed during the period, 59% in men and 53% in patients younger than 1 year. Seventy seven percent of procedures were done in an examination room, using a nasal approach. The main indication was visualization of the airway (49%). The most common clinical diagnosis, in descending order were: atelectasis, stridor and etiologic study of pneumonia by bronchoalveolar lavage (BAL). In children younger than 6 months the most common clinical diagnosis was stridor, followed by atelectasis. The main diagnosis in the whole sample, reached by FB was atelectasis secondary to mucous plug. In children younger than 6 months, the main diagnosis was laryngomalacia. A positive microbial culture was obtained in 43% of patients in whom BAL was done. Complications were uncommon (5%) and mostly mild. In 2.3% of cases, these were severe, such as bronchospasm and need for mechanical ventilation. Severe complications were observed in patients younger than 3 months with severe stridor or in children with cancer, who required FB and BAL. CONCLUSIONS: Flexible bronchoscopy is a safe and useful procedure in pediatric patients.