Related Experiment Video

Updated: Aug 19, 2026

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels
05:31

Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels

Published on: August 7, 2017

The international study of asthma and allergies in childhood (ISAAC): phase three rationale and methods

P Ellwood1, M I Asher, R Beasley

  • 1Department of Paediatrics, The University of Auckland, Auckland, New Zealand. p.ellwood@auckland.ac.nz

The International Journal of Tuberculosis and Lung Disease : the Official Journal of the International Union Against Tuberculosis and Lung Disease
|January 29, 2005
PubMed

Insights

The International Study of Asthma and Allergies in Childhood (ISAAC) investigated global symptom prevalence of asthma and allergies in children. Phase Three aims to map worldwide trends and uncover causes of these common childhood conditions.

Area of Science:

  • Pediatric Allergy and Immunology
  • Epidemiology
  • Global Health

Background:

  • The International Study of Asthma and Allergies in Childhood (ISAAC) was established in 1991 to investigate the causes of asthma, allergic rhinoconjunctivitis, and atopic eczema in children globally.
  • Phase One revealed significant international variations in symptom prevalence, which current knowledge cannot fully explain.
  • Subsequent phases aimed to explore risk and protective factors contributing to these observed differences.

Purpose of the Study:

  • To determine the global prevalence of asthma and allergic disease symptoms in children.
  • To analyze recent time trends in symptom prevalence worldwide.
  • To investigate the underlying causes (aetiology) of asthma and allergic diseases in diverse populations.

Main Methods:

  • ISAAC Phase Three replicated Phase One methodology with enhanced standardization across numerous international centers.
  • Data collection involved standardized questionnaires administered to children and adolescents.
  • The study involved over 280 centers in 106 countries, facilitating large-scale data acquisition.

Main Results:

  • Phase One identified substantial global disparities in the prevalence of asthma and allergy symptoms.
  • Phase Two focused on identifying environmental and genetic factors influencing these differences.
  • Phase Three aimed to provide a comprehensive global map of symptom prevalence and trends.

Conclusions:

  • ISAAC Phase Three provides a detailed global overview of asthma and allergy symptom prevalence and trends in children.
  • The findings contribute to a better understanding of the aetiology of these conditions worldwide.
  • International collaboration and standardized methods are crucial for global epidemiological research.

More Related Videos

A Component-resolved Diagnostic Approach for a Study on Grass Pollen Allergens in Chinese Southerners with Allergic Rhinitis and/or Asthma06:34

A Component-resolved Diagnostic Approach for a Study on Grass Pollen Allergens in Chinese Southerners with Allergic Rhinitis and/or Asthma

Published on: June 4, 2017

Related Concept Videos

Asthma I: Introduction01:28

Asthma I: Introduction

Asthma is a chronic inflammatory disorder of the airways characterized by variable airflow obstruction and heightened bronchial responsiveness to a wide range of triggers. The underlying inflammation leads to airway swelling, mucus hypersecretion, and smooth muscle constriction, all of which narrow the airway lumen and impede airflow. Clinically, asthma presents with recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing, symptoms that typically vary in intensity and...
Asthma-IV: Diagnostic and Management01:30

Asthma-IV: Diagnostic and Management

The diagnosis and management of asthma are comprehensive, encompassing clinical assessments, lung function tests, and pharmacological interventions. Here's an overview:
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
Asthma III: Clinical Manifestations01:13

Asthma III: Clinical Manifestations

Asthma presents with a characteristic pattern of episodic respiratory symptoms that reflect underlying airway inflammation, bronchoconstriction, and mucus hypersecretion. Although severity varies among individuals, certain clinical manifestations are considered hallmarks of the disorder and often guide diagnosis and assessment.Respiratory SymptomsA persistent cough is one of the most common early features of asthma. It is frequently dry and tends to worsen at night or in the early morning,...
Asthma-II: Pathophysiology and Classification01:26

Asthma-II: Pathophysiology and Classification

Asthma is a prevalent chronic respiratory condition marked by inflammation and hyperresponsiveness of the airways. Its pathophysiology involves complex interactions among inflammatory pathways, immune responses, and neural mechanisms.
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
Asthma-III: Symptoms and Complications01:24

Asthma-III: Symptoms and Complications

Asthma, a common chronic respiratory condition, is classified considering the frequency and severity of symptoms alongside lung function impairment. Understanding this classification is essential for appropriate treatment and management. Here's a detailed look at the classification of asthma and its clinical features and complications:
Classification of Asthma
Asthma-I: Introduction01:29

Asthma-I: Introduction

Asthma is a chronic respiratory ailment that requires careful management due to its varying symptoms and influencing factors. It is characterized by airway inflammation, bronchial hyperresponsiveness, and reversible airflow obstruction, leading to symptoms like wheezing, shortness of breath, chest tightness, and coughing. The symptom frequency and intensity may vary considerably over time. It is also linked to immune system responses to allergens and irritants, highlighting the complex...