Prevalence of atopic eczema and related symptoms in Brazilian schoolchildren: results from the International Study of Asthma and Allergies in Childhood (ISAAC) phase 3.

Background: International comparisons of the prevalence of atopic eczema and related symptoms are scarce. The standardized protocol of the International Study of Asthma and Allergies in Childhood (ISAAC) facilitates investigation of prevalence all over the world.

Objective: To apply the ISAAC written questionnaire to evaluate the prevalence of atopic eczema and related symptoms among 6-7 year-old children and 13-14 year-old adolescents living in 20 Brazilian cities.

Methods: The ISAAC written questionnaire was filled in by 23,422 children aged 6-7 years and 58,144 adolescents aged 13-14 years living in 2 population centers in the north, 8 in the northeast, 1 in the midwest, 5 in the southeast, and 5 in the south.

Results: The prevalence of flexural eczema (itchy rash ever in characteristic places in the last 12 months) ranged from 5.3% to 13.0% for children and was lower among the adolescents (range, 3.4%-7.9%). Among children, the highest rates were observed in population centers in the northeast, mainly along the coast. Among adolescents the highest rates were observed in the north and northeast, mainly in Natal, Aracaju, and Vitória da Conquista. The northeastern countryside had higher prevalence rates of severe eczema (kept awake at night by this itchy rash in the last 12 months) in comparison to northeastern coastal centers. There was a significant correlation between the prevalence of flexural eczema and severe eczema for both age groups, separately (6-7 year-olds, prho= 0.756, P<.004; 13-14 year-olds, rho=0.874, P<.0001) or grouped (6-7 plus 13-14 years-olds, rho=0.696, P<.0001).

Conclusion: The prevalence of eczema and related symptoms is variable in Brazil, where the highest prevalence is found in the north and northeast; on the other hand, a higher prevalence of severe eczema was observed in Brazilian centers in the south.