Obstructive sleep apnea syndrome in obese Singapore children.

We set out to determine the prevalence of obstructive sleep apnea syndrome (OSAS) among obese Singapore school children and identify risk factors for OSAS. This study was designed as a prospective study in three phases. Parents completed a questionnaire with regards to sleep and daytime symptoms in Phase 1. Children suspected to have OSAS based on the questionnaire and all with a percent ideal body weight (IBW) >/=180 were called for clinic visits in Phase 2. All whose percent IBW >/=180 and those in whom the physicians strongly suspected OSAS were subjected to a polysomnogram in phase 3. The children were recruited from the School Health Nutritional Clinic for obese children. The investigations were carried out at Tan Tock Seng Hospital. In all, 3,671 children were screened with the questionnaire. Of these, 146 were selected to undergo polysomnography. Twenty-six had abnormal sleep studies with apnea/hypoxia indices (AHIs) >5/hr. The significant clinical feature which correlated with OSAS was sleep sitting up (P = 0.005). The risk is higher in morbidly obese (IBW >/=180), with a prevalence of 13.3% (8/60), than in less obese children (IBW <180). One in eight (12.5%) of these children was asymptomatic and would have been missed based on the questionnaire. Presence of adenotonsillar hypertrophy led to increased risk of OSAS. The prevalence of OSAS was 0.7% (26/3,671) among the obese schoolchildren in Singapore, which is similar to the prevalence reported by others. Using discriminant analysis, the estimated prevalence increased to 5.7%. In the morbidly obese (IBW >/=180), the prevalence rate is higher at 13.3%.

Experience with video-assisted thoracoscopic surgery in the management of complicated pneumonia in children.

PURPOSE: The aim of this study was to assess the impact of video assisted thoracoscopic surgery (VATS) in the management of empyema in children. METHODS: This report involves cases of complicated pneumonia in children requiring surgical intervention after failure of medical treatment with antibiotics, with or without drainage from November 1997 to October 1999. The impact of VATS has been studied prospectively from October 1998 when VATS was introduced. The results have been compared with the previous year when similar cases were dealt with open thoracotomy. These 2 groups of patients with VATS (V) or without VATS (O) were studied for their progress in hospital and the final outcome. RESULTS: A total of 39 immunocompetent children with community-acquired pneumonia were studied. There were 17 cases in O and 22 in V. There were 2 conversions to open thoracotomy in V. Both of these cases required resection of the lung parenchyma for severe necrosis and bronchopleural fistula. The mean age in years was 5.3 (O) and 4.9 (V). Parameters that were significantly less in V compared with O include timing of referral (O, 13.6 days; V, 5.3 days), number of lung resections (O, 8; V, 2), blood transfusion (O, 14; V, 2), analgesia requirements (O, 7.8 days; V, 2.9 days), postoperative length of stay in hospital (O, 10.4 days; V, 4.6 days), time to become normothermic (O, 5.6 days; V, 1.7 days); and time to removal of chest drains (O, 6.0 days; V, 2.7 days). Cosmesis is superior in cases of VATS compared with open thoracotomy. All the children recovered well on follow-up with resolution of symptoms and no recurrences. CONCLUSIONS: (1) VATS has ushered in a new era of hope for patients with complicated pneumonia. (2) Thoracotomy, lung resections, and the attending morbidity rate have decreased. (3) Patients are being referred earlier by the physicians because the management protocol is changing.

Asthma in Singapore children.

Over the last decade, admissions from respiratory infections have declined but there had been an increase in admissions from Bronchial Asthma in Singapore Government Hospitals. Better recognition by doctors and increased prevalence are important factors. However, mortality had remained low. Like other mortality studies, underestimation of the severity of asthma and undertreatment are the major contributing factors to asthma deaths in Singapore children. Therefore, better public education and continuing education of medical personnel may help to reduce deaths from asthma in children and adolescents.

Efficacy of bronchodilators in the treatment of bronchiolitis.

UNLABELLED: Bronchiolitis is a common respiratory infection affecting young children. Much controversy revolves around the efficacy of bronchodilators in the treatment of bronchiolitis. This study was conducted to address this issue. AIM: To determine the efficacy of bronchodilators in the treatment of bronchiolitis. METHOD: All children less than 2 years old with bronchiolitis were randomly assigned to receive nebulisations of Salbutamol, Ipratropium bromide or normal saline. A fourth group given only humidified oxygen without nebulisation were used as a control. RESULTS: Data were obtained for 120 patients. Fifty-one (42%) had respiratory syncytial virus (RSV) isolated from their nasopharyngeal aspirates. The demographic characteristics of the 4 groups were similar. There was no significant difference between the groups in terms of severity score, number of nebulisations required in the nebulised groups and the outcome as measured by the length of hospitalisation. CONCLUSION: The use of bronchodilators did not alter the course of the disease and is therefore not effective in the treatment of bronchiolitis.

Etiology of acute severe lower respiratory tract infection in hospital-based patients.

Acute respiratory infections are common childhood illnesses. Most are mild and self-limiting. Five percent are lower respiratory tract diseases and are potentially serious. A prospective study was conducted to ascertain the etiology of community-acquired severe lower respiratory tract infections (LRTI) in hospital based patients. Mycoplasma was the most frequently identified agent (33%). This was followed by viruses (28%) and bacteria (15%). Twenty-four percent of children had no identified causative agent.

Paradoxical vocal cord dysfunction: when a wheeze is not asthma.

Vocal cord dysfunction (VCD) is an uncommon condition which often mimics asthma in presentation and severity. We present nine- and 11-year-old female siblings with vocal cord dysfunction, which is a dysfunction of the larynx involving unintentional paradoxical adduction of the vocal cords during inspiration. We evaluated the use of exercise testing in conjunction with pulmonary function testing in suspected vocal cord dysfunction. Although normal pulmonology function tests were elicited with the patient at rest, exercise testing revealed blunting of the expiratory loop with attenuation of the inspiratory loop unique to VCD. The child underwent video laryngoscopy in the specialised voice clinic, which confirmed vocal cord dysfunction. Exercise testing is a rapid and noninvasive means of diagnosing vocal cord dysfunction in a small subset of patients, but video laryngoscopy, with training manoeuvres to elicit paradoxical vocal cord movements in VCD, remains the gold standard of diagnosis of VCD.

The changing face of food hypersensitivity in an Asian community.

BACKGROUND: Food allergy seems to be increasing in Asia as well as world-wide. Our aim was to characterize food protein sensitization patterns in a population of Asian children with possible food allergy. METHODS: Children presenting to our allergy clinic over 3 years with symptomatic allergic disease and at least one specific food allergen sensitization documented on skin prick testing were included in the analysis. RESULTS: Two hundred and twenty-seven patients fulfilled inclusion criteria. Ninety (40%) of the positive skin tests were positive to egg, 87 (39%) to shellfish, 62 (27.3%) to peanut, 30 (13.2%) to fish, 27 (11.8%) to cow's milk, 21 (9.3%) to sesame, 13 (3.7%) to wheat and eight (3.2%) to soy. Peanut sensitization was the third most common sensitizing allergen, and seen mostly in young atopic children with multiple food hypersensitivities and a family history of atopic dermatitis. The median reported age of first exposure to fish and shellfish was 6 and 12 months, respectively. The mean age at presentation of children with shellfish hypersensitivity was at 6.7 years of age. The likelihood of shellfish sensitization was increased in children with concomitant sensitization to cockroaches. CONCLUSIONS: In contrast to previously reported low peanut allergy rates in Asia, in our review, peanut sensitization is present in 27% (62/227) of food-allergic children, mostly in patients with multiple food protein sensitizations. Temporal patterns of first exposure of infants to fish and shellfish are unique to the Asian diet. Shellfish are a major sensitizing food source in Asian children, especially in allergic rhinitis patients sensitized to cockroaches.

Sensitization to dust mites in children with allergic rhinitis in Singapore: does it matter if you scratch while you sneeze?

BACKGROUND: Previously published data established Blomia tropicalis, as the major source of allergic sensitization in asthmatic children in tropical Singapore. Objective To define the prevalence, clinical characteristics and risk factors of species-specific mite sensitization in paediatric allergic rhinitis (AR) patients in this unique environment. METHODS: We performed a prospective evaluation of newly diagnosed AR patients, from 1 May 2003 to 30 April 2004, from the otolaryngology and allergy outpatient clinics of the Kendang Kerbau Children's Hospital in Singapore. Patients included in the study showed evidence of sensitization to at least one respiratory allergen source and completed a detailed questionnaire. Relative risk of sensitization and associated risk factors were calculated using logistic regression analysis with the forward stepwise model. Multivariate regression analysis was performed to adjust for confounding interactions. Continuous values were compared using anova, SPSS 9.0 for Windows (SPSS Inc., 1999). RESULTS: One hundred and seventy-five patients were included, 119 (68%) males, 142 (81%) Chinese, age mean 7.9 years (range 2-16). Sixty-eight patients (39%) reported a concomitant diagnosis and/or clinical complaints of bronchial asthma and 84 (48%) of atopic dermatitis. Skin prick test results were positive for traditional house dust mites (Dermatophagoides pteronyssinus. and D. farinae mix) in 85% of patients and for B. tropicalis in 62%. Overall mite sensitization was 98%, household pets 10%, moulds 9% and food proteins 12%. By far the single most significant factor associated with Dermatophagoides sensitization in this group was the presence of allergic eczema (odds ratio (OR) 31.8%, 95% confidence interval (CI) 3.6-285, P=0.002). Allergic eczema was negatively associated with B. tropicalis sensitization (OR 0.26%, 95% CI 0.14-0.5). CONCLUSIONS: Children with AR and concomitant atopic dermatitis show a preferential sensitization to the Dermatophagoides mites. In our population, B. tropicalis sensitization is more prominent in children with pure respiratory allergy.

Bronchial asthma in Singapore children.

The incidence of bronchial asthma admissions to Singapore's major Paediatric Units has increased over the years. The diagnosis of asthma was usually simple but patients with atypical presentations required the demonstration of bronchial lability to confirm the diagnosis. National statistics revealed a small but constant number of deaths from asthma in childhood. Underestimation of severity and delay in treatment were important contributing factors to deaths from asthma.

Congenital tuberculosis.

A neonate presented with poor feeding, jaundice and hepatosplenomegaly. He was in liver failure with disseminated coagulopathy. Post-mortem liver biopsy revealed discrete granulomas with central necrosis and acid-fast bacilli on Ziehl-Nielsen's stain. The mother had active tuberculosis at delivery. The principal characteristics of congenital tuberculosis are reemphasized in this observation.

Efficacy of Zaditen (ketotifen) in wheezy infants and young children.

This was a double-blind, randomised evaluation of the efficacy and safety of Zaditen in comparison with placebo in infants and young children (aged 6-36 months). These children either had (i) at least 2 episodes of wheezing over 8 weeks, or (ii) persistent wheeze over 4 weeks, prior to entering into the study. In the doctor's opinion, the group treated with Zaditen had more improvement in symptomatology (p < 0.05). They were more likely to have reduced or discontinued bronchodilators. They showed trends of improvement of symptom scores in night cough, wheeze and sputum production. These differences, however, did not reach statistical significance. There were no major adverse reaction of note.

Reproducibility of hyperventilation of cold dry air in children with cystic fibrosis.

Wheezing is a significant problem in some patients with cystic fibrosis. Currently available tests are not reliable at determining whether this wheezing is due to co-existent asthma or to the underlying pulmonary disease. The reproducibility of hyperventilation of cold dry air (HVCDA) was studied over eight days in 11 children with cystic fibrosis. A group with mild lung disease were selected to minimize the variability due to underlying pulmonary disease. Fifty-six per cent of subjects had consistent responses to HVCDA. A test of reproducibility was performed on the respiratory heat exchange, the percentage fall in FEV1 after HVCDA and the ratio of these two (R). Respiratory heat exchange was found to be highly reproducible with a reproducibility co-efficient of 0.97. The percentage fall in FEV1 after HVCDA and R were not reproducible over the eight-day period. Hyperventilation of cold dry air did not give reproducible results in children with cystic fibrosis, suggesting that a single test may not be suitable for judging bronchial liability.

Severe acute respiratory syndrome in Singapore.

AIMS: To describe the epidemiological and clinical features of paediatric severe acute respiratory syndrome (SARS) in Singapore. METHODS: The following data were retrospectively collected from the case records of all 71 patients (aged 7 months to 14 years) admitted from 23 March to 22 May 2003 to the SARS paediatric unit: patient demographics, contact history, clinical features, physiological parameters, investigations, treatment, and outcome. Using WHO criteria there were seven probable (P), 23 suspect (S), and 41 observe (O) cases. RESULTS: Compared to the O cases P patients had a longer mean duration of fever (3.66 (SD 2.3) v 8.57 (SD 2.44) days), lower mean thrombocytopenia (248.3 (SD 82.7) v 173.7 (SD 49.0)x10(9)/l), leucopenia (8.19 (SD 4.45) v 3.06 (SD 1.02)x10(9)/l), lymphopenia (2.79 (SD 1.97) v 1.44 (SD 0.75)x10(9)/l), and neutropenia (4.48 (SD 2.88) v 1.24 (SD 0.43)x10(9)/l). Chest auscultation was abnormal in 71% of P patients, with mild crepitations detected. All had abnormal chest radiographs versus 39% of S cases, and 27% of O cases. CONCLUSIONS: There are no distinguishing clinical features of paediatric SARS. The diagnosis is suggested by the paucity of clinical signs with an abnormal chest radiograph, and laboratory evidence of leucopenia, lymphopenia, and thrombocytopenia.

Lung function after pertussis.

The relationship between pertussis infection and subsequent abnormalities of pulmonary function is not clear. Thirty subjects (16 male, 14 female) aged 14.3 years (s.e.m. = 1.9) were studied who had been hospitalized with culture-proven pertussis when less than 6 months of age. Details of respiratory symptoms in the subjects and their families were obtained. Standard spirometry, lung volumes by body plethysmography, maximum flows at low lung volumes and histamine challenges were performed. Nine of 30 (30%) subjects were symptomatic with a history of recurrent cough and wheeze while 11 of 30 (37%) had abnormal pulmonary function tests. Seven of nine symptomatic subjects had abnormal pulmonary function including positive histamine challenges. Twenty-one per cent had a family history of asthma. This study indicates that children hospitalized in infancy with pertussis can subsequently be shown to have recurrent lower airways symptomatology and abnormal pulmonary function, but the incidence is not significantly higher than a control group from the same socio-economic background.

The changing trend in the pattern of infective etiologies in childhood acute lower respiratory tract infection.

The etiologic agents causing acute lower respiratory tract infection (LRTI) in hospitalized children were compared for 1995 and 1988. Between May 1994 to April 1995, 397 children were admitted to Tan Tock Seng Hospital for acute LRTI compared to 240 children in 1988. The following criteria for LRTI were used: (i) age less than 12 years with a community-acquired LRTI; (ii) presence of cough or fever of less than 2 weeks' duration; and (iii) presence of tachypnea, chest retractions or pulmonary infiltrates on chest X-ray. Sputum cultures were considered suitable for culture if there were less than 25 epithelial cells per low power field. Moraxella catarrhalis was considered only if heavy growth of more than 3+ was seen. Etiological agents were found in about 70% of patients in both studies. Viruses constituted 41.3% of the etiologic agents in 1995 but constituted only 28% in 1988; 36% had a bacterial etiology in 1995 compared to 15% in 1988. The most common bacteria in 1995 was M. catarrhalis (34.7%) followed by non-type B Haemophilus influenzae (33%). In contrast, in 1988, Mycoplasma (33%) was the predominant organism followed by H. influenzae (17%) and M. catarrhalis (11.4%). The increased incidence of M. catarrhalis could be due to antibiotic selection. A mixed viral-bacterial etiology was found in 12.3% of the 1995 cohort. The majority of the bacteria were positive by sputum cultures; only 4 (3.3%) had positive blood cultures. No penicillin resistance was detected in 1988; however, in 1995, penicillin resistance was found in 17% of the Streptococcus pneumoniae, 38.5% of H. influenzae and 83% of M. catarrhalis. It was also found that 30% of the S. pneumoniae were also resistant to erythromycin, and 23% were resistant to sulfamethoxaxole-trimethoprim; 5% of the H. influenzae had multiple resistance to erythromycin, sulfamethoxazole-trimethoprim and chloramphenicol. Among those patients with antibiotic resistance, 30% had received prior antibiotics of which 18% had had two or more antibiotics, frequently erythromycin or amoxycillin/ampicillin. Judicious use of antibiotics is required to check the rising trend of antibiotic resistance.

Effects of inhaled corticosteroid on bone turnover in children with bronchial asthma.

Long-term usage of systemic steroids is associated with multiple side effects. One of the major morbidities is due to its effect on bone metabolism leading to bone loss and resulting in skeletal fractures. This study was conducted to determine the effects of inhaled steroids on bone mineral density (BMD) and biochemical bone markers. Twenty-four children with frequent episodic or mild persistent asthma who satisfied the clinical criteria for starting on inhaled corticosteroids (ICS) were enrolled into the study. The BMD scan was done using dual energy X-ray absorptiometry, prior to starting ICS therapy and 6 months later. Biochemical markers of bone metabolism, (i) serum osteocalcin as a bone formation marker, and (ii) urinary deoxypyridinoline (Upd) as a bone resorption marker, were taken prior to ICS treatment and at 2 monthly intervals. The biochemical markers were all taken in the morning. Twenty-four, age- and sex-matched children with mild episodic asthma, not requiring ICS, were used as controls for the BMD measurements. The BMD scan was done upon enrollment into the study and 6 months later. Twenty-four children on ICS and 24 controls completed the study. The subjects were on a mean dose of beclomethasone dipropionate (BDP) 0.4 mg/day. One subject needed a short course of Prednisolone in the early treatment period. None of the controls needed oral steroid therapy. One child in the control group sustained a greenstick fracture after an accidental fall. The mean rate of change of BMD was 1.8% +/- 12.3 in the subjects on BDP. This was lower than the 6.1% +/- 10.6 among the control subjects. However, this difference did not reach statistical significance (P = 0.16). There was a significant increase in serum osteocalcin level after 6 months of BDP treatment from 66.83 +/- 22.71 ng/mL to 81.61 +/- 24.66 ng/mL (P < 0.005). There was a decline in Upd from 36.2 +/- 47.1 nmol/mmol creatinine to 21.4 +/- 6.92 nmol/mmol creatinine. However, this did not reach statistical significance. There was no difference in the statural gain between the subjects on ICS and their controls. This study showed that 6 months of ICS therapy (mean dose 0.4 mg/day) had no significant adverse effect on bone metabolism in asthmatic children.

Enteroviral meningitis in neonates.

We present 4 neonates with enteroviral meningitis. The cerebrospinal fluid findings were variable and posed a diagnostic problem. Immediate outcome was excellent and 3 of the 4 infants were normal at follow-up at 6 months of age. However long-term follow-up will be necessary to to determine any long-term sequelae.

Edible "bird's nest"-induced anaphylaxis: An under-recognized entity?

The Chinese delicacy "bird's nest" is the most common cause of food-induced anaphylaxis requiring hospitalization among Chinese children in Singapore. This investigation has established an immunoglobulin E-mediated cause and has characterized the major putative allergens.

Complications of severe lower respiratory tract infections in Singapore children.

Over one year period, 240 children with severe lower respiratory infection was admitted to a general paediatric department. The mortality was 1.6%. Apart from pleural effusions and skin exanthems, several major complications were noted. These were septicaemia (1), apnoea (2), encephalopathy (3), meningitis (1), Stevens Johnson Syndrome (1), bronchiectasis (1) and lung abscess (1).