At preschool ages, its prevalence varies from 1% to 17.5%, between 5 and 16 years it varies from 1% to 13.5%, and in adults its range is from 1% to 4% 1, 2.
En preescolares la prevalencia varía de 1% a 17,5%, entre los 5 y 16 años de 1% a 13,5% y del 1% al 4% en adultos 1,2.