Dermatophagoides Farinae, an Important Allergenic Substance in Buckwheat-Husk Pillows

ABSTRACT

Inhalation of buckwheat flour as well as ingestion of buckwheat foods induces bronchial asthma. The buckwheat flour attached to the husks used as bed pillow filling can provoke bronchial asthma in patients sensitized to buckwheat. In Korea one third of the pillows contain buckwheat husk (BH). Recently the authors examined three asthmatics who presented symptoms when exposed to house dust extract and BH-pillow extract. They had no history of asthma attack following ingestion of buckwheat foods. The possibility of mites or mite like substances in the BH-pillow extract was evaluated. There was a good correlation of skin test results between Dermatophagoides farinae (D. farinae) and BH-pillow extract. The concentrated extract of BH-pillow displayed inhibition of D. farinae radioallergosorbent test (RAST) and a dose dependent pattern RAST inhibition. The lyophilized extract of BH-clean did not show any constant feature in D. farinae RAST inhibition test. Furthermore, mites of Dematophagoides species were discovered in the contents of BH-pillows. Ten of 40 cases who tested positive to the skin test for the extract of BH-pillow manifested weakly positive to buckwheat RAST. None of them presented a previous history of buckwheat food allergy. Also we evaluated the possibility of cross-allergenicity between buckwheat and its husk. Using these results the authors concluded that there were some amounts of allergenic substance from house dust mites in the contents of BH-pillows and that the dust from these could provoke or aggravate the symptoms of asthmatics who were sensitive to house dust mites.