Incidence and prevalence of children’s diffuse lung disease in Spain

Abstract

Background: Children’s diffuse lung disease, also known as children’s Interstitial Lung Diseases (chILD), are a heterogeneous group of rare diseases with relevant morbidity and mortality, which diagnosis and classification are very complex, and epidemiological data are scarce.

Objective: To analyse incidence and prevalence of chILD in Spain.

Methods: Multicentre observational prospective study in patients under 18 years of age with chILD during 2018 and 2019 in Spain.

Results: A total of 380 cases with chILD were notified from 51 paediatric pulmonology units all over the country, covering a paediatric population of 7,644,155 in 2018 and 7,636,093 in 2019. The average incidence of paediatric diffuse lung disease was 8.18 new cases/million of children per year (CI95% 6.28-10.48). The average prevalence of paediatric diffuse lung disease was 46.39 cases/million of children (CI95% 41.69-51.48). The age group with the highest prevalence were children under 1 year of age. Different types of disorders were seen in children 2 to 18 years of age compared with children 0 to 2 years of age. Most frequent cases were: primary pulmonary interstitial glycogenosis in neonates (14/62), neuroendocrine cell hyperplasia of infancy in infants (44/144), idiopathic pulmonary hemosiderosis in children 1-5 years old (13/74), hypersensitivity pneumonia in children 5-10 years old (9/52), and scleroderma in older than 10 years old (8/48). The 9.5% (36/380) of cases had a disease causing mutation, and same number (36/380) had no clear aetiology.

Conclusions: We found an incidence and prevalence of chILD much higher than previously described probably due to greater understanding and increased clinician awareness of these rare diseases.