Innes Asher

Worldwide variations in the prevalence of symptoms of atopic eczema in the international study of asthma and allergies in childhood

BACKGROUND Little is known about the prevalence of atopic eczema outside Northern Europe. OBJECTIVES We sought to describe the magnitude and variation in the prevalence of atopic eczema symptoms throughout the world. METHODS A cross-sectional questionnaire survey was conducted on random samples of schoolchildren aged 6 to 7 years and 13 to 14 years from centers in 56 countries throughout the world. Those children with a positive response to being questioned about the presence of an itchy relapsing skin rash in the last 12 months that had affected their skin creases were considered to have atopic eczema. Children whose atopic eczema symptoms resulted in sleep disturbance for 1 or more nights per week were considered to have severe atopic eczema. RESULTS Complete data was available for 256,410 children aged 6 to 7 years in 90 centers and 458,623 children aged 13 to 14 years in 153 centers. The prevalence range for symptoms of atopic eczema was from less than 2% in Iran to over 16% in Japan and Sweden in the 6 to 7 year age range and less than 1% in Albania to over 17% in Nigeria for the 13 to 14 year age range. Higher prevalences of atopic eczema symptoms were reported in Australasia and Northern Europe, and lower prevalences were reported in Eastern and Central Europe and Asia. Similar patterns were seen for symptoms of severe atopic eczema. CONCLUSIONS Atopic eczema is a common health problem for children and adolescents throughout the world. Symptoms of atopic eczema exhibit wide variations in prevalence both within and between countries inhabited by similar ethnic groups, suggesting that environmental factors may be critical in determining disease expression. Studies that include objective skin examinations are required to confirm these findings.

Prevalence of asthma symptoms in Latin America: The international study of asthma and allergies in childhood (ISAAC)

The prevalence of respiratory symptoms indicative of asthma in children from Latin America has been largely ignored. As part of the International Study of Asthma and Allergies in Childhood (ISAAC), 17 centers in 9 different Latin American countries participated in the study, and data from 52,549 written questionnaires (WQ) in children aged 13–14 years and from 36,264 WQ in 6–7 year olds are described here.

Global burden of asthma among children.

About 334 million people worldwide suffer from asthma, and this figure may be an underestimation. It is the most common chronic disease in children. Asthma is among the top 20 chronic conditions for global ranking of disability-adjusted life years in children; in the mid-childhood ages 5-14 years it is among the top 10 causes. Death rates from asthma in children globally range from 0.0 to 0.7 per 100 000. There are striking global variations in the prevalence of asthma symptoms (wheeze in the past 12 months) in children, with up to 13-fold differences between countries. Although asthma symptoms are more common in many high-income countries (HICs), some low- and middle-income countries (LMICs) also have high levels of asthma symptom prevalence. The highest prevalence of symptoms of severe asthma among children with wheeze in the past 12 months is found in LMICs and not HICs. From the 1990s to the 2000s, asthma symptoms became more common in some high-prevalence centres in HICs; in many cases, the prevalence stayed the same or even decreased. At the same time, many LMICs with large populations showed increases in prevalence, suggesting that the overall world burden is increasing, and that therefore global disparities in asthma prevalence are decreasing. The costs of asthma, where they have been estimated, are relatively high. The global burden of asthma in children, including costs, needs ongoing monitoring using standardised methods.

International patterns of the prevalence of pediatric asthma the ISAAC program.

Like so much research, the findings from the ISAAC program have raised more questions than they have answered. Despite their limitations, the ISAAC findings provide the basis for further studies to investigate factors that potentially contribute to these international patterns and may lead to novel public health and pharmacologic intervention strategies that reduce the prevalence and severity of asthma worldwide.

Asthma in the global NCD agenda: a neglected epidemic

96 www.thelancet.com/respiratory Vol 1 April 2013 this. Smoking will lead to both an increase in lung density by infl ammation (bronchitis, bronchiolitis) and a decrease in lung density by emphysematous destruction. The eff ect of smoking cessation greatly overrides the annual decline of lung density. Shaker and colleagues followed up 254 current smokers with annual CT scans, 36 of whom had quit smoking, and their PD15 fell by –4·9 HU, more than four times the annual decline in continuing smokers. In summary, the annual decline in lung density in COPD patients is subtle and can be aff ected by many confounding factors, especially smoking. Under strict measures, quantitative CT can be applied in clinical trials to measure this decline, but most likely not without forcing a substantially reduced sample size and trial duration. It is also not ready for clinical practice. Morphological phenotyping of airway disease and emphysema complemented by fi ssure analysis should initially be used for stratifi cation of COPD. Additional image-based functional assessments of perfusion and ventilation with quantitative readouts 1,10 can be extremely helpful to show regional functional compensation mechanisms. Quantitative, regional morphological data from CT scans, and additional image-driven functional information, could together provide a strong basis to choose the appropriate targeted therapy in COPD patients—beyond smoking cessation—such as interventional or surgical options.

Does urban extent from satellite images relate to symptoms of asthma, rhinoconjunctivitis and eczema in children? A cross-sectional study from ISAAC Phase Three

Abstract Objective: The relationship between urbanisation and the symptom prevalence of asthma, rhinoconjunctivitis and eczema is not clear, and varying definitions of urban extent have been used. Furthermore, a global analysis has not been undertaken. This study aimed to determine whether the symptom prevalence of asthma, rhinoconjunctivitis and eczema in centres involved in the International Study of Asthma and Allergies in Childhood (ISAAC) were higher in urban than rural centres, using a definition of urban extent as land cover from satellite data. Methods: A global map of urban extent from satellite images (MOD500 map) was used to define the urban extent criterion. Maps from the ISAAC centres were digitised and merged with the MOD500 map to describe the urban percentage of each centre. We investigated the association between the symptom prevalence of asthma, rhinoconjunctivitis and eczema and the percentage of urban extent by centre. Results: A weak negative relationship was found between the percentage of urban extent of each ISAAC centre and current wheeze in the 13–14-year age group. This association was not statistically significant after adjusting for region of the world and gross national income. No other relationship was found between urban extent and symptoms of asthma, rhinoconjunctivitis and eczema. Conclusions: In this study, the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema in children were not associated with urbanisation, according to the land cover definition of urban extent from satellite data. Comparable standardised definitions of urbanisation need to be developed so that global comparisons can be made.

Dedicated paediatric teaching remains critical to the undergraduate medical curriculum.

Paediatrics, the branch of medicine responsible for the health and medical care of infants, children and adolescents from birth to young adulthood, is a relatively recent speciality with its origins in the mid-19th century 1. Unlike many other areas of practice, the population it serves is unable to advocate for itself. This often results in paediatrics being overlooked in planning services and education. One should note that a long protected childhood is unique to our species and essential for human mental and physical health 2. Dedicated paediatric teaching in the undergraduate/postgraduate medical curriculum is essential, irrespective of the intended area of practice for the doctors in training. The reasons for this are as follows.