Fibrosing alveolitis in infancy and childhood.

Fibrosing alveolitis is a rare, diffuse lung disease characterized by varying combinations of two histological features: thickening of alveolar walls and the presence of large mononuclear cells in the alveolar spaces. Clinical details of 10 children with fibrosing alveolitis are reported. The main symptoms in children are tachypnoea or dyspnoea, cough, poor weight gain, and cyanosis. The condition is similar to that in adults, but it is usually a more acute illness, and if untreated, more predictably fatal. Respiratory failure, pulmonary hypertension, and cardiac failure are the major complications. Less commonly, superimposed bacterial infection and pneumothorax occur. Chest x-rays often show a sequence of changes with a ground-glass appearance and fine mottling in the early stage of the disease, progressing to a picture of mainly hilar linear markings in those children who recover. The histological features at lung biopsy or necropsy are described; these correlated poorly with the radiological features, steroid responsiveness, and clinical course. Lung function tests in 3 older children showed evidence of markedly reduced lung volumes in 2. Static lung compliance in 4 children in the acute stage of the illness was normal in 3 and diminished in one. The response to steroid therapy was analysed in cases from the literature and the 10 reported cases. No spontaneous remissions occurred, all the survivors having been treated with corticosteroids. In children fibrosing alveolitis is almost always a corticosteroid-responsive disease. An appropriate course of prednisolone would be of at least 4 week's, but preferably of 8 weeks' duration, at a minimum daily dose of 2 mg/kg. After improvement the steroid withdrawal should be cautious and protracted, comprising at least a year's continuous treatment.