Diagnostic and therapeutic evaluation of Blomia tropicalis in patients with allergic rhinitis.

AIM: To assess the clinical relevance of B. tropicalis IgE sensitization through nasal challenge test (NCT) and explore the effectiveness of immunotherapy (AIT) with this mite.

METHODS

A prospective cohort study was conducted in patients with moderate/severe persistent allergic rhinitis. In phase one, atopy tests for B. tropicalis were evaluated using NCT as reference parameter. In phase two, NCT-positive patients underwent AIT for 1 year, followed by a second NCT.

RESULT: Eighty patients sensitized to B. tropicalis were enrolled; 56% had a positive baseline NCT. The SPT and sIgE exhibited a sensitivity over 90%, but a specificity lower than 50% with an overall diagnostic accuracy of 64%. The sIgE to Blo t 5 exhibited a sensitivity of 59.9%, specificity of 80%, and overall diagnostic accuracy 72%. Of those with positive NCT, 39 started AIT. During the second NCT, 82% of these patients tolerated a B. tropicalis extract concentration tenfold higher than baseline.

CONCLUSION

B. tropicalis is clinically relevant for allergic rhinitis patients, but atopy tests for this disease have a low specificity. AIT with B. tropicalis is a therapeutic tool for allergic rhinitis, mainly when a positive-NCT is demonstrated.