Diffuse lung disease in children also called children’s interstitial lung disease which are associated with significant morbidity and mortality that represent clinically by dispnea, tachypnea, hypoxemia.
The disease can involve the alveoli, airway vessels, lymphatic channel & pleural space  classification system in neonate & infant consist of diffuse developmental disorder  such as alveolar growth  disorder, surfactant dysfunction,  neuroendocrine cell hyperplasia of infancy,  pulmonary interstitial glycogenesis but disorder of childhood has  different  cause such as  of pulmonary alveolar protenosis/ hemorrhage
Lymphangectasia & lymphagiomatosis,  bronchiolit oblitrans, …
Diagnosis regarding progressive respiratory symptom, associated with CXR, HRCT findings is suggested also in some of case lung biopsy should be considered