Summary Serological measurements of specific IgE to Dermatophagoides farinae, D. pteronyssinus and grass pollen showed statistically highly significant correlations with prick test reactions, the sizes of weals elicited, nasal tests and the clinical history. In subjects with negative prick tests, intracutaneous tests gave reactions which were not associated with specific IgE or reactions to nasal tests. Highly significant correlations were also found between total IgE values and prick test reactions to the allergens tested and to 48/80 but not to histamine; there was a negative correlation with reactions to anti‐IgE serum. The reactions to prick tests identified almost all subjects with specific IgE.

Skin tests were performed on 210 patients with house dust allergy and bronchial asthma or perennial rhinitis using extracts of Dermatophagoides pteronyssinus and of four storage mites most commonly found in house dust in the United Kingdom-Acarus siro. Tyrophagus putrescentiae. Lepidoglyphus (formerly Glycyphagus) destructor and Glycyphagus domesticus. The results of the skin tests were related to certain occupations and living conditions of the patients which could have exposed them to storage mites and some patients were included because their environment seemed especially likely to expose them to these species in order to assess the importance of these conditions. D. pteronyssinus was the most potent of the mite allergens and provoked the largest number of positive tests but a proportion of the storage mite species gave skin reactions which were larger or as large as those of D. pteronyssinus. No significant statistical correlation was found between reactions to D. pteronyssinus and any storage mite but highly significant correlations were found between some storage species. The frequency and strength of reactions to these species were unexpectedly high in view of their irregular occurrence and relative scarcity in house dust.It is suggested that sensitisation to these species occurs through exposure either to localised sources of infestation overlooked during the random collection of floor or bedding dust or to infested materials encountered at work or other activities or to infested food or bedding of certain domestic pets. It is concluded that allergy to storage mites is more important and widespread than hitherto realised and is a considerable occupational hazard in farming communities and to those in occupations handling infested materials. Storage mites may also be important allergens for those living in very damp houses where the growth of moulds may encourage the development of Glycyphagus domesticus or other mites.

The relationships of total and specific IgE levels to the clinical manifestations and atopic status of ninety-two subjects, suffering from asthma, rhinitis and infantile eczema in varying combinations, were examined. No significant correlations were found between specific IgE levels to Dermatophagoides spp. and grass pollen or between total IgE levels, and the age of the patient, nor the age of onset, duration, severity and frequency of symptoms. A highly significant correlation was found between total IgE levels and the numbers of skin test reactions to a battery of twenty routine tests and to the sum total of the graded sizes of the reactions in each subject.