Visual analogue scale ( VAS ) was used to assess the symptoms among the control group and the various intervention groups and the enzyme linked immunosorbent assay ( ELISA ) was applied to detect the contents of histamine , leukotriene C@ ( LTC@ ) , house dust mite D@ specific IGE ( sIGE ) and eosinophil cationic protein ( ECP ) among the control group and the various intervention groups .