Allergens and antigens of Dermatophagoides farinae.

Extracts of Dermatophagoides farinae cultured on Gaines dog-meal plus yeast, and in particular the `protein' fraction precipitated by ammonium sulphate, give stronger skin test reactions in house dust sensitive patients than extracts of Dermatophagoides pteronyssinus and of house dust. Specific IgE was found against the D. farinae extract in eighteen out of twenty house dust sensitive subjects. Precipitins were found in human sera against extracts of D. farinae, D. pteronyssinus and house dust and also against antigens in cereal and vegetable dusts. These precipitin tests provided evidence of related antigens in extracts of house dust and D. farinae and in extracts of house dust and D. pteronyssinus, but not in D. farinae and D. pteronyssinus.