Skin testing in predicting response to nasal provocation with alternaria.

OBJECTIVE

Examine the efficacy of epicutaneous and intradermal testing in predicting response to nasal provocation with Alternaria antigen.

STUDY DESIGN AND SETTING

Prospective study. Subjects were tested with the Multi-Test II (MT) epicutaneous testing device. Subjects with negative wheals were then tested with a 1:500 weight:volume intradermal injection of Alternaria. They had baseline assessment of nasal cross-sectional area (CSA) using acoustic rhinometry and underwent nasal provocation with increasing Alternaria concentrations. CSA was assessed at each concentration. A nasal allergen provocation score (NAP) of nasal symptoms as well as a nasal visual analogue scale (VAS) were also completed with each concentration.

RESULTS

Sensitivity and specificity of MT in predicting nasal response to Alternaria were poor at 42% and 44%, respectively. The addition of intradermal testing increased sensitivity only modestly to 58%. hierarchical linear modeling analysis demonstrated that subjects positive to Alternaria on skin testing did not show a significant reduction in nasal CSA on acoustic rhinometry or significant elevations in two nasal symptom scores with direct nasal provocation.

CONCLUSION AND SIGNIFICANCE

Skin testing with either epicutaneous or intradermal testing may not be an accurate or sufficient technique in the assessment of Alternaria reactivity. These results suggest that mold allergies may involve more complex immune mechanisms than simply an immunoglobulin (Ig)E mediated type I immediate hypersensitivity response alone. An alternate model for mold sensitivity, as well as modifications in testing methods, may be required in the evaluation of mold allergy.