Pediatric allergic diseases in the Indian subcontinent—Epidemiology, risk factors and current challenges

Abstract

Introduction: India is low-middle-income country (LMIC) with a population of 1.3bn, comprising about 20% of the global population. While the high-income Western countries faced an "allergy epidemic" during the last three decades, there has been a gradual rise in prevalence of allergic diseases in India. Methods: Narrative review. Results and Discussion: Allergic diseases occur as a consequence of a complex interplay between genetic and environmental factors. There are multiple contrasting determinants that are important to consider in India including high levels of air pollution, in particular PM 2.5 due to burning of fossil fuels and biomass fuels, diverse aero-biology, tropical climate, cultural and social diversity, religious beliefs/myths, linguistic diversity, literacy level, breastfeeding and weaning, diet (large proportion vegetarian), and high incidence rates of TB, HIV, malaria, filariasis, parasitic infestations, and others, that not only shape the immune system early in life, but also impact on biomarkers relevant to allergic diseases. India has a relatively weak and heterogeneous healthcare framework, and allergology has not yet been recognized as an independent specialty. There are very few postgraduate training programs, and allergic diseases are managed by primary care physicians, organ-based specialists, and general pediatricians. Adrenaline auto-injectors are not available, there is patient unaffordability for inhalers, nasal sprays, and biologics, and this is compounded by poor compliance leading to 40%-50% of asthmatic children having uncontrolled disease and high rates of oral corticosteroid use. Standardized allergen extracts are not available for skin tests and desensitization. This article provides a critical analysis of pediatric allergic diseases in India.

Allergic disease prevalence in school children in Bengaluru, India: A cross‐sectional survey

“…It is the second-most populous country comprising 20% of the global population. Whilst India has not faced an "allergy epidemic" as in High-Income Countries (HICs), there is some evidence that the burden of allergic diseases has gradually risen 1 , and is greatly magnified by the absolute numbers and is compounded by the unmet demand for allergy services 2,3 . Data regarding epidemiology, risk factors and natural course of allergic diseases in India are relatively sparse.…”

“…ETS is a recognized risk factor affecting asthma control and antenatal exposure significantly enhances risk of wheeze in the child. 3,7 The median hair nicotine levels in Indian women have been reported to be greater 8 than in western countries and the nature of ETS in India is different, as 72% smoke "bidi's". 3 Presence of a co-existing allergic disease enhanced the odds of another allergic disease, which is a well-recognized phenomenon and serves as an internal validation for our data set.…”

Comments on vitamin D in asthma, milk allergy diagnosis, and stem cell transplantation in chronic granulomatous disease

“…The study was performed in India, a country with increasing numbers of allergic children, but also increasing research in this field. 4 Data from the ESDAC trial published here by Jat and colleagues were obtained from 250 children randomly supplemented with vitamin D or receiving placebo. 5 The measured outcome after 9 month of treatment was based on a childhood asthma control test score.…”

“…It is a tradition that the editorial highlights three articles, and the first one selected is a trial on the efficacy of vitamin D supplementation in asthmatic children. The study was performed in India, a country with increasing numbers of allergic children, but also increasing research in this field 4 . Data from the ESDAC trial published here by Jat and colleagues were obtained from 250 children randomly supplemented with vitamin D or receiving placebo 5 .…”

Pathogenesis of asthma and characterization of fish allergens

“…From the beginning, PAI has been a truly worldwide journal for pediatric allergists, and this strong commitment to geographic diversity continues. In this issue, you will find a review article from a group of pediatric allergists from the Indian subcontinent addressing current knowledge and future challenges in childhood allergy in this area of the world 1 …”