Diagnosis of asthma in children: the contribution of a detailed history and test results.

INTRODUCTION: There are few data on the usefulness of different tests to diagnose asthma in children. AIM: We assessed the contribution of a detailed history and a variety of diagnostic tests for diagnosing asthma in children. METHODS: We studied children aged 6-16 years referred consecutively for evaluation of suspected asthma to two pulmonary outpatient clinics. Symptoms were assessed by parental questionnaire. The clinical evaluation included skin-prick tests, measurement of exhaled nitric oxide fraction (F eNO), spirometry, bronchodilator reversibility and bronchial provocation tests (BPT) by exercise, methacholine and mannitol. Asthma was diagnosed by the physicians at the end of the visit. We assessed diagnostic accuracy of symptoms and tests by calculating sensitivity, specificity, positive and negative predictive values and area under the curve (AUC). RESULTS: Of the 111 participants, 80 (72%) were diagnosed with asthma. The combined sensitivity and specificity was highest for reported frequent wheeze (more than three attacks per year) (sensitivity 0.44, specificity 0.90), awakening due to wheeze (0.41, 0.90) and wheeze triggered by pollen (0.46, 0.83) or by pets (0.29, 0.99). Of the diagnostic tests, the AUC was highest for F eNO measurement (0.80) and BPT by methacholine (0.81) or exercise (0.74), and lowest for forced expiratory volume in 1 s (FEV1) (0.62) and FEV1/forced vital capacity ratio (0.66), assessed by spirometry. CONCLUSION: This study suggests that specific questions about triggers and severity of wheeze, measurement of F eNO and BPT by methacholine or exercise contribute more to the diagnosis of asthma in school-aged children than spirometry, bronchodilator reversibility and skin-prick tests.

Do clinical investigations predict long-term wheeze? A follow-up of pediatric respiratory outpatients.

INTRODUCTION: The contribution of clinical investigations to prediction of long-term outcomes of children investigated for asthma is unclear. AIM: We performed a broad range of clinical tests and investigated whether they helped to predict long-term wheeze among children referred for evaluation of possible asthma. METHODS: We studied children aged 6 to 16 years referred to two Swiss pulmonary outpatient clinics with a history of wheeze, dyspnea, or cough in 2007. The initial assessment included spirometry, fractional exhaled nitric oxide, skin prick tests, and bronchial provocation tests by exercise, methacholine, and mannitol. Respiratory symptoms were assessed with questionnaires at baseline and at follow-up 7 years later. Associations between baseline factors and wheeze at follow-up were investigated by logistic regression. RESULTS: At baseline, 111 children were examined in 2007. After 7 years, 85 (77%) completed the follow-up questionnaire, among whom 61 (72%) had wheeze at baseline, while at follow-up 39 (46%) reported wheeze. Adjusting for age and sex, the following characteristics predicted wheeze at adolescence: wheeze triggered by pets (odds ratio, 4.2; 95% CI, 1.2-14.8), pollen (2.8, 1.1-7.0), and exercise (3.1, 1.2-8.0). Of the clinical tests, only a positive exercise test (3.2, 1.1-9.7) predicted wheeze at adolescence. CONCLUSION: Reported exercise-induced wheeze and wheeze triggered by pets or pollen were important predictors of wheeze persistence into adolescence. None of the clinical tests predicted wheeze more strongly than reported symptoms. Clinical tests might be important for asthma diagnosis but medical history is more helpful in predicting prognosis in children referred for asthma.

Pseudomonas aeruginosa in public swimming pools and bathroom water of patients with cystic fibrosis.

INTRODUCTION: Acquisition of Pseudomonas aeruginosa (PA) in the lungs of patients with cystic fibrosis (CF) is a marker of poor survival. PA is a ubiquitous pathogen prevalent in humid conditions. This study aimed to identify the prevalence of PA in public swimming pools, as well as from water taps. METHODS: Water was collected from public indoor and outdoor pools in the area of St. Gallen, Switzerland. In addition, standing and running water was sampled from bathroom water taps of 50 patients with CF. RESULTS: Outdoor pools: In 2002, none of the 72 specimens from 28 pools revealed PA. In 2003, three specimens from 46 pools (7%) revealed PA, each were from a different paddling pool. Indoor pools: two of 128 specimens from 56 pools (4%) identified PA, both were from non-public hydrotherapy pools. Water taps: in winter, none of the 102 specimens was colonized with PA. in summer, only two out of 50 specimens of the standing water were positive for PA but none of the running water revealed PA. CONCLUSION: The prevalence of PA in public swimming pools and bathroom water taps in the eastern part of Switzerland is very low. On hot summer days, outdoor paddling pools and standing tap water can contain PA. This study does not support recommendations to avoid public swimming pools or running tap water if the water is maintained according to hygiene guidelines.