Methods: Cross-sectional study, 101 participants with rhinitis diagnosed according to ARIA (89.1% with asthma); age range 6-15 years. SPT was done with Dermatophagoides pteronyssinus (Dp), Blattella germanica (Bg), cat and dog allergenic extracts (IPI ASAC Brasil); a mean wheal diameter of ≥ 2 mm greater than the negative control was considered positive. Sera were analysed for allergen specific IgE antibodies to Dp (Der p 1, Der p 2), Bg (Bla g 1, Bla g 2, Bla g 4, Bla g 5), cat (Fel d 1, Fel d 2) and dog (Can f 1, Can f 2) allergens using a microarray system (ImmunoCAP ISAC, PMD, Austria), considered positive ≥ 0,3 ISU (ISAC standardized units). Categorical variables were shown as percentage and differences between the two methods verified by chi-square test; p<0.05 was considered significant.
Results: SPT was positive to Dp in 88.1% whereas ISAC was positive to Der p 1 in 74.2% (p<0.001) and Der p 2 in 73.3% (p<0.01) respectively. Sensitivity of SPT was 97% and specificity was 38%. The remaining allergens caused less SPT reactions (cockroach 25.7%, cat 22.8%, dog 27.7%) and these were associated with lower detection of specific-IgE by ISAC respectively Bla g 1 (0.9%, p=0.09), Bla g 2 (0%), Bla g 4 (0%), Bla g 5 (0.9%, p=0.55); Fel d 1 (16.8%, p<0.01), Fel d 2 (0.9%, p=0.06); Can f 1 (4.9%, p=0.53), Can f 2 (2.9%, p<0.001).
Conclusions: SPT remains the favored method to detect IgE-mediated sensitivity to aeroallergens. SPT was highly sensitive for Dp though less specific in comparison with the IgE microarray to Der p 1 and Der p 2 allergens.