Background: Skin tests are the most used diagnostic method of allergic rhinitis, which, in addition to identify specific allergen, can determine the relative sensitivity of one patient to the allergen.
Objective: To assess the association between skin test reactivity and total and specific serum IgE levels on the diagnosis of patients with perennial allergic rhinitis.
Material and methods: We measured the response to skin test reactivity and total and specific serum IgE levels in 69 patients with perennial allergic rhinitis.
Results: The skin test reactivity showed responses to: Dermatophagoides pt in 62 patients (90%), house dust in 57 (83%), cat in 41 (59%), dog in 23 (33%), and Lolium p in 16 (23%). The mean level of total IgE was of 378 UI (19 to 4,036) and that of specific IgE was of 39.2 UI (0.2 to 98.6). Total IgE > 200 UI was observed in fifty two patients (75%), which was significantly lesser than the frequency of specific IgE > 0.35 UI (at least for an allergen), which was 94% (p < 0.05, Z). At least two tests of skin reactivity were positive for 90% of the patients. This frequency was similar to the 95% for the specific IgE but different to the 75% for the total IgE (p < 0.05, X2). The correlation between the results of the skin test reactivity and the specific seric IgE showed Spearman r from 0.23 to 0.35 (p < 0.05). The correlation between the total IgE and the specific IgE showed a Spearman r of 0.08 (p < 0.05) and between the total IgE and the skin test reactivity an r of 0.15 (p < 0.05).
Conclusion: In the diagnosis of perennial allergic rhinitis, the results of the skin test reactivity and the specific serum IgE are correlated but these two results are non consistent with the results of the total serum IgE.