Chronic pneumonitis in infancy was first described by Katzenstein et al. [4] . The clinical and radiologic features are similar to those observed in other forms of ILD. Specific histologic abnormalities include diffuse thickening alveolar septa, hyperplasia of type 2 AEC, and presence of primitive mesenchymal cells within the alveolar septa. In some cases, foci of pulmonary proteinosis-like material have been observed in air spaces. The prognosis has been reported to be poor with a high mortality rate.