Management of children with interstitial lung diseases: The difficult issue of acute exacerbations

Interstitial lung disease (ILD) in children (chILD) is an umbrella term for a wide spectrum of rare diseases affecting the lung parenchyma, the causes of which often remain undetermined. These diffuse lung disorders are chronic, and often have high morbidity and mortality [1\u20133]. The epidemiology of the various forms of chILD is difficult to establish. Extrapolations from small studies have suggested an approximate incidence of 0.5\u20130.8 cases per 100\u200a000 children [4, 5] However, this is certainly an underestimation due to the lack of standardised definitions, the inadequacy of organised reporting systems, and the variety of pathological conditions. In addition, clinical presentation is often nonspecific, contributing to a poor recognition of these disorders and confusion with other chronic pulmonary diseases. Insufficient disease-specific knowledge creates particular challenges for medical professionals, caregivers and chILD patients. Within the international community of clinicians and researchers involved in paediatric parenchymal lung diseases, the need for multicentre collaborations has resulted in the formation of networks of expertise to improve and harmonise approaches to diagnosis and management of the various forms of chILD. In this context, the present article reports expert opinions on the definition and diagnosis of acute exacerbations, which are major unpredictable deleterious episodes of acute worsening with significant morbidity that punctuate disease course