Mites and house dust allergy

Summary 279 patients, most of whom had perennial asthma or perennial rhinitis, were tested intradermally with extracts of Dermatophagoides pteronyssinus and D. farinae in order to ascertain the incidence of positive skin reactions. The great majority of house dust sensitive patients had positive skin reactions to both mite extracts. However, the concordance between house dust and mite extract positive skin reactions, though statistically significant, did not reach the extent found in other countries. Of the three extracts employed, D. pteronyssinus appeared to contain the most potent allergen while its culture medium extract yielded a low percentage of positive skin reactions. These results suggest that, in italy also, mites seem to represent the most important allergenic source of house dust.