This article provides a descriptive study on the prevalence and control of severe childhood asthma in Japan. Using data from the National Database of Health Insurance Claims and Specific Health Checkups, the study found that the national prevalence of severe asthma in children aged 0-5 years was 11.0 per 100,000 persons, and for children aged 6-11 years, it was 22.8 per 100,000 persons in 2019. The study reveals a decrease in the prevalence of severe childhood asthma over the past decade, but a significant proportion of children with severe asthma still had uncontrolled symptoms and required regular oral corticosteroid use. The study suggests the need for reevaluating current asthma management and developing new treatments to address these clinical concerns. However, the study acknowledges limitations, such as the lack of validation for diagnostic codes and the potential underestimation of uncontrolled asthma due to the absence of pulmonary function tests in the data. [Extracted from the article]