[Interstitial pulmonary diseases]

Interstitial pneumonia is a rare disease, posing a diagnostic challenge to pneumologists, pediatricians, radiologists and pathologists. Only by the combined efforts of the European Respiratory Society (ERS) and the American Thoracic Society (ATS) has has been possible to standardize the formerly different European and Northern American nomenclature of interstitial lung diseases (alveolitis versus interstitial pneumonia) in adults and to clearly and unambiguously define the diagnostic criteria. The ATS/ERS classification of 2002 comprises seven entities: usual interstitial pneumonia (UIP), non-specific interstitial pneumonia (NSIP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), cryptogenic organizing pneumonia (COP), lymphocyte interstitial pneumonia (LIP), and acute interstitial pneumonia (AIP). Using the ATS/ERS classification of interstitial pulmonary diseases in premature infants, infants and children is problematic, since UIP, RB-ILD and AIP do not occur at this age. Although infants with severe respiratory insufficiency may sometimes show morphological features similar to DIP or NSIP, this entity should rather be classified as chronic pneumonitis of infancy (CPI) because of differences in etiology, pathogenesis and prognostic outcome.