Oh Moh Chay

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.

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.

Early Presentation With Angioedema and Urticaria in Cross-reactive Hypersensitivity to Nonsteroidal Antiinflammatory Drugs Among Young, Asian, Atopic Children

Objective. Nonsteroidal antiinflammatory drugs (NSAIDs), mainly ibuprofen, are used extensively among children as analgesic and antipyretic agents. Our initial survey in the Kendang Kerbau Childrens Hospital in Singapore showed NSAIDs to be the second most common adverse drug reaction-causing medications among children of Asian descent. We attempted to characterize the clinical and epidemiologic profile of NSAID reactions in this group of patients. Methods. A retrospective case series from a hospital-based pediatric drug allergy clinic was studied. A diagnosis of NSAID hypersensitivity was made with a modified oral provocation test. Atopy was evaluated clinically and tested with a standard panel of skin-prick tests. We excluded from analysis patients with any unprovoked episodes of urticaria and/or angioedema, patients <1 year of age, and patients who refused a diagnostic challenge test. Results. Between March 1, 2003, and February 28, 2004, 24 patients, including 14 male patients (58%) and 18 Chinese patients (75%), with a mean age of 7.4 years (range: 1.4–14.4 years), were diagnosed as having cross-reactive NSAID hypersensitivity. A family history consistent with NSAID hypersensitivity was elicited for 17% of patients. None of the patients reported any episodes of angioedema/urticaria unrelated to NSAIDs. The median cumulative reaction-eliciting dose was 7.1 mg/kg. Facial angioedema developed for all patients (100%) and generalized urticaria for 38% of challenged patients, irrespective of age. There was no circulatory compromise, but respiratory symptoms of tachypnea, wheezing, and/or cough were documented for 42% of patients. A cross-reactive hypersensitivity response to acetaminophen was documented for 46% of our patients through their history and for 25% through diagnostic challenge. Compared with patients with suspected adverse drug reactions to antibiotics, patients in the NSAID group were older (7.4 vs 4.8 years) and more likely to have a diagnosis of asthma (odds ratio: 7.5; 95% confidence interval: 3.1–19). Conclusions. Early presentations of facial angioedema and urticaria are key features of dose- and potency-dependent, cross-reactive reactions to NSAIDs in a subpopulation of young, Asian, atopic children. Significant overlap with acetaminophen hypersensitivity, especially among very young patients, for whom the use of a cyclooxygenase-2-specific medication may not be feasible, severely limits options for medical antipyretic treatment.

Influenza vaccine concurrently administered with a combination measles, mumps, and rubella vaccine to young children

Children aged 11 to <24 months received 2 intranasal doses of live attenuated influenza vaccine (LAIV) or placebo, 35+/-7 days apart. Dose 1 was administered concomitantly with a combined measles, mumps, and rubella vaccine (Priorix). Seroresponses to measles and mumps were similar between groups. Compared with placebo, response rates to rubella in LAIV+Priorix recipients were statistically lower at a 15 IU/mL threshold (83.9% vs 78.0%) and the prespecified noninferiority criteria were not met. In a post hoc analysis using an alternate widely accepted threshold of 10 IU/mL, the noninferiority criteria were met (93.4% vs 89.8%). Concomitant administration with Priorix did not affect the overall influenza protection rate of LAIV (78.4% and 63.8% against antigenically similar influenza strains and any strain, respectively).

Epidemiology, clinical characteristics and antimicrobial resistance patterns of community-acquired pneumonia in 1702 hospitalized children in Singapore

Objective and background:  Childhood community‐acquired pneumonia (CAP) remains a leading cause of morbidity and mortality worldwide. The features of childhood CAP vary between countries. The aim of this study was to delineate the clinical characteristics, complications, spectrum of pathogens and patterns of antimicrobial resistance associated with hospitalized cases of childhood CAP in Singapore.

Aeroallergen sensitization in pediatric allergic rhinitis in Singapore: Is air-conditioning a factor in the tropics?

Singapore is a unique blend of a tropical environment with a high standard of hygiene and public health care. The objective was to define the prevalence, clinical characteristics, and environmental risk factors of specific aeroallergen sensitization in pediatric allergic rhinitis patients in this unique environment. The method adopted was a retrospective analysis of allergic rhinitis patients, undergoing aeroallergen skin prick testing (SPT), in the outpatient specialty clinic of the KK Childrens hospital, from July 2001 to June 2002. A total of 202 patients were included, 161 (80%) males, 167 (83%) Chinese, age mean 7.6 yr (range 2–14 yr). The most prevalent clinical symptoms were: watery rhinorrhea 61%, blocked nose 61%, sneezing 52%, snoring 17%, and epistaxis 12%. SPT results were positive for house dust mites in 97% of children, pets (20%), molds (19%), pollens (15%), and kapok (10%). Mold sensitization was significantly more prevalent in households without air‐conditioning (aircon), 49% vs. 10% with aircon (odds ratio 9.4, 95% CI 3.8–22.9). Polysensitization (sensitization to three or more allergens) was similarly more prevalent in households without aircon, 51% vs. 14% with aircon (odds ratio 6.4, 95% CI 2.8–14.7). It was concluded that indoor aeroallergen sensitization is the major associated factor with clinical allergic rhinitis in children in Singapore. Patients living in households without air‐conditioning are at increased risk of mold sensitization and polysensitization.

Paediatric anaphylaxis in a Singaporean children cohort: changing food allergy triggers over time.

Background We have noticed changes in paediatric anaphylaxis triggers locally in Singapore. Objective We aimed to describe the demographic characteristics, clinical features, causative agents and management of children presenting with anaphylaxis. Methods This is a retrospective study of Singaporean children presenting with anaphylaxis between January 2005 and December 2009 to a tertiary paediatric hospital. Results One hundred and eight cases of anaphylaxis in 98 children were included. Food was the commonest trigger (63%), followed by drugs (30%), whilst 7% were idiopathic. Peanut was the top food trigger (19%), followed by egg (12%), shellfish (10%) and birds nest (10%). Ibuprofen was the commonest cause of drug induced anaphylaxis (50%), followed by paracetamol (15%) and other nonsteroidal anti-inflammatory drugs (NSAIDs, 12%). The median age of presentation for all anaphylaxis cases was 7.9 years old (interquartile range 3.6 to 10.8 years), but food triggers occurred significantly earlier compared to drugs (median 4.9 years vs. 10.5 years, p < 0.05). Mucocutaneous (91%) and respiratory features (88%) were the principal presenting symptoms. Drug anaphylaxis was more likely to result in hypotension compared to food anaphylaxis (21.9% vs. 2.7%, Fishers exact probability < 0.01). There were 4 reported cases (3.6%) of biphasic reaction occurring within 24 h of anaphylaxis. Conclusion Food anaphylaxis patterns have changed over time in our study cohort of Singaporean children. Peanuts allergy, almost absent a decade ago, is currently the top food trigger, whilst seafood and birds nest continue to be an important cause of food anaphylaxis locally. NSAIDs and paracetamol hypersensitivity are unique causes of drug induced anaphylaxis locally.

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.

Allergic rhinitis and non-allergic rhinitis in children in the tropics: prevalence and risk associations.

The age‐related comparative prevalence of allergic rhinitis (AR) and non‐allergic rhinitis (NAR) in children is poorly defined. We aimed to characterize AR and NAR in children.

Hypersensitivity to Paracetamol in Asian Children with Early Onset of Nonsteroidal Anti-Inflammatory Drug Allergy

Background: The published incidence of paracetamol cross-reactivity in adults and adolescents with nonsteroidal anti-inflammatory drug (NSAID) reactions is low and all data on such reactions in young children is sparse. The study aim was to characterize the clinical presentation and cross-reactivity with paracetamol in patients with a reported onset of NSAID hypersensitivity before 6 years of age. Methods: A retrospective case review was done of patients with cross-reactive hypersensitivity reactions to antipyretic/analgesic medications from the pediatric allergy clinic of the Kendang Kerbau Hospital, Singapore. Included patients reported the onset of such reactions before 6 years of age. Hypersensitivity was established through a detailed history of recurrent reactions to NSAIDs or an oral provocation test. Results: Eighteen patients fulfilled the diagnostic criteria within the study period. Eighty-three percent had cross-reactive reactions with paracetamol. When compared to the group of children with later onset of NSAID hypersensitivity, children with onset before 6 years of age had a significantly increased likelihood of reacting to paracetamol (odds ratio 9.6, 95% confidence interval 1.6–58.0, p < 0.05). Conclusion: Paracetamol seems to be a major eliciting drug in this group of children.