[Sensitization to Blomia tropicalis and Dermatophagoides pteronyssinus, farinae and siboney prevalence in patients with rhinitis, allergic asthma, or both, in a population of a metropolitan area of Mexico City].

BACKGROUND

The increased prevalence of asthma has been associated with an increase in atopic sensitization, and it is parallel with similar increases in other allergic diseases. In United States, Blomia tropicalis has the fourth place between the most known types of house dust mites, and is the most common in the southern subtropical states. In Mexico there have been few studies to investigate sensitization to this mite.

OBJECTIVE

To identify the prevalence of sensitization to Blomia tropicalis and Dermatophagoides in patients with rhinitis and/or allergic bronchial asthma in a population of the metropolitan area of Mexico.

PATIENTS AND METHOD: We selected 334 patients with a diagnosis of rhinitis and/or bronchial asthma, 149 men and 185 women, aged between 3 and 74 years, of which 189 had positive skin tests to at least one of the mites (Dermatophagoides and/or Blomia tropicalis). We measured the wheal area and compared the averages of the surface of the wheal and correlations were made of the results using the Pearson correlation coefficient.

RESULTS

The total number of patients who presented positive skin test to Blomia tropicalis in association with other mites was 53 (28.0%) and the total number of patients who presented positive skin test to only Blomia tropicalis was 23 (12.1%). Correlations of r = 0.45, 0.45 and 0.68 (statistically significant, p < 0.05) were found between the three species of Dermatophagoides, while there was no correlation between positive dermoreactions of Blomia tropicalis with those of Dermatophagoides.

CONCLUSIONS

In the metropolitan area of Mexico City, while not having a tropical or sub-tropical weather, it is important to include Blomia tropicalis in diagnostic panels of allergens.