Abstract
Transient airways obstruction associated with reduction in the transfer factor (diffusing capacity) of the lungs is reported in a patient with a clinical syndrome in keeping with extrinsic allergic alveolitis after exposure to Ramin dust (Gonystylus bancanus). The alterations in pulmonary function were consistently demonstrated on testing the patient in his working environment and were reproduced in the laboratory after inhalational challenge. The importance of the temporal relationship of changes in pulmonary function to contact with suspected allergenic material is emphasized.