[Seasonal changes in specific IgE: the acarid Dermatophagoides pteronyssinus]

The authors have studied monthly the titres of specific IgE to Dermatophagoides pteronyssinus, by Phadebas RAST, in 8435 measurements, spread over 4 years. Significant seasonal and monthly variations were seen every year with a maximum level in the autumn or the beginning of winter, with a second peak at the end of winter in 3 years of the 4. There was no close superposition of pattern form one year to another. The domestic relative humidity had a significant effect on the seasonal variation with a mean shift of 2 months that could be explained by the length of the biological cycle of the mites. These data compare with those of the literature (sampling of mites in bedding, longitudinal studies...).