Is the desert lung syndrome (nonoccupational dust pneumoconiosis) a variant of pulmonary alveolar microlithiasis? Report of 4 cases with review of the literature.

Four cases of pulmonary alveolar microlithiasis are presented. These patients had heavy exposure to sand particles for long periods. This is to hypothesize that those sand particles are responsible for triggering a hyperimmune response resulting in the formation of microlithiasis. Previously expressed theories had linked microlithiasis to external irritants and the condition has similarities with desert lung syndrome, a disease definitely caused by the deposition of sand silica in the lungs.