Causes of pulmonary alveolar proteinosis in different age groups

Schematic diagram showing the main causes of PAP in different age groups. The height of each row is not proportionate to the relative frequency. Autoimmune PAP represents approximately 90% of cases overall but is less common in children.

In this diagram, the black bars represent the typical age of presentation, the white bar indicates limited evidence for this age group, and the dashed lines indicate that the disorder can present at any age.