Epidemiology and spontaneous improvement of secretory otitis.

The results of 25 repetitive impedance screenings of three cohorts of children are presented. The point prevalence of a type B tympanogram was 13% at the end of the first year of life, 11-18% during the second, third, fourth and fifth year of life, decreasing to 7% during the sixth and seventh year of life. The period prevalence during the first year of life was 15% and at least 30% during the second, third, fourth and fifth year of life, indicating that about 80% of all healthy children have had at least one period with a type B tympanogram and 40% have had at least one recurrent episode. Spontaneous improvement of secretory otitis occurs frequently, and it is recommended to wait 3-6 months before instituting surgical treatment.