Chronic interstitial lung disease in children

Chronic interstitial lung disease (ILD) is rare in children, but is clinically relevant because of its high morbidity and mortality rates. Several aetiological agents may have a role in this disease and various aetiopathogenic forms have been described, although they share a characteristic evolution towards pulmonary fibrosis. The aetiology sometimes remains unknown, in which case we speak of idiopathic interstitial pneumonia (IIP). Diagnosis relies on non-invasive methods (clinical history, respiratory function tests, chest X-ray and high-resolution CT scan) and invasive techniques (bronchoalveolar lavage, transbronchial biopsy, video-assisted thoracoscopic biopsy and open lung biopsy); the latter are used when the former fail to identify an aetiological agent. The gold standard for the diagnosis is lung biopsy, however, which also enables the classification of the idiopathic forms, in particular (usual interstitial pneumonia, desquamative interstitial pneumonia, non-specific interstitial pneumonia, and so on). In ILD, the most common therapeutic approaches involve the use of oral steroids and hydroxychloroquine sulphate for its anti-inflammatory and antifibrotic effect. The prognosis is often poor.