Secondary interstitial lung disease in childhood and adulthood

Secondary interstitial lung disease (ILD) in childhood and adulthood (Orphanet code 264944) refers to a broad category of diffuse parenchymal lung disorders that arise as a consequence of known underlying conditions or exposures, rather than occurring as primary idiopathic entities. These secondary causes include autoimmune and connective tissue diseases (such as systemic lupus erythematosus, rheumatoid arthritis, and systemic sclerosis), drug-induced lung toxicity, radiation therapy, infections, aspiration syndromes, hypersensitivity pneumonitis from environmental or occupational exposures, and metabolic storage disorders, among others. The disease primarily affects the lung interstitium — the tissue and space surrounding the air sacs (alveoli) — leading to inflammation, fibrosis, or both. This results in impaired gas exchange and progressive respiratory compromise. Key symptoms include chronic cough, progressive exertional dyspnea (shortness of breath), reduced exercise tolerance, and in some cases digital clubbing and cyanosis. In children, failure to thrive and recurrent respiratory infections may be prominent features. High-resolution computed tomography (HRCT) of the chest typically reveals characteristic patterns such as ground-glass opacities, reticular markings, or honeycombing depending on the underlying etiology and stage of disease. Treatment is directed at the underlying cause whenever possible. This may include withdrawal of offending drugs, avoidance of environmental triggers, immunosuppressive therapy for autoimmune-related ILD (such as corticosteroids, mycophenolate mofetil, or rituximab), and antifibrotic agents in cases with progressive fibrosis. Supportive care includes supplemental oxygen, pulmonary rehabilitation, and in severe end-stage cases, lung transplantation may be considered. Prognosis varies widely depending on the specific etiology, the degree of fibrosis at diagnosis, and the response to treatment of the underlying condition.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Secondary interstitial lung disease in childhood and adulthood