Dyspnea and pulmonary function in the L-tryptophan-associated eosinophilia-myalgia syndrome

We reviewed the pulmonary history, dyspnea ratings, and pulmonary function test results in 16 patients with L-tryptophan-induced eosinophilia myalgia syndrome to determine the correlation between reported pulmonary complaints and pulmonary function abnormalities. All patients reported pulmonary symptoms. Dyspnea, seen in 14 of 16 (87 percent) patients, was the most common symptom. The severity of dyspnea was graded by the baseline dyspnea index and the oxygen cost diagram. Pulmonary function testing including maximal static inspiratory and expiratory pressures were measured. The DCO was diminished in 12 of 16 (75 percent) patients. The MSIP was decreased in seven out of ten (70 percent) and the MSEP was decreased in nine out of ten (90 percent) of those patients tested. There was a statistically significant correlation between the severity of dyspnea as graded by the BDI and OCD, and the decrease in DCO. These results and a review of the literature of the pulmonary manifestations of EMS lead us to conclude that patients with EMS have a high prevalence of dyspnea, and it appears to be caused by both lung parenchymal involvement, as well as respiratory muscle weakness.