Hericium erinaceum (yamabushitake) extract-induced acute respiratory distress syndrome monitored by serum surfactant proteins.

This is the first report suggesting a causal relationship between acute respiratory distress syndrome and Hericium erinaceum extract, which is commercialized as a diet food. A 63-year-old man was admitted to our hospital for intensive care of severe acute respiratory failure with diffuse infiltration in both lungs. Bronchoalveolar lavage fluid revealed a high percentage of lymphocytes. Lymphocyte stimulation test showed a strong reactivity against extract formulation of Hericium erinaceum (Yamabushitake), which he had taken four months before onset. He recovered with successful steroid pulse therapy under mechanical ventilation. Concentrations of surfactant protein (SP)-A and SP-D in sera reflected the clinical features.