Prick and intradermal tests compared with specific IgE in allergic assessment

Area of Science:

• Allergy and Immunology
• Respiratory Medicine

Background:

• Allergic assessment in patients with respiratory symptoms often involves multiple diagnostic tests.
• These tests, including skin prick tests, intradermal reactions, and specific IgE measurements, can yield conflicting results, complicating diagnosis.

Purpose of the Study:

• To compare the diagnostic concordance and utility of skin prick tests, intradermal reactions, and serum-specific IgE measurements in evaluating symptomatic outpatients.
• To determine the optimal sequence and combination of these tests for accurate allergic assessment.

Main Methods:

• Sixty outpatients with seasonal or periannal respiratory symptoms were evaluated.
• Participants underwent skin prick tests, intradermal reactions, and serum-specific IgE (Immunoglobulin E) determination for eight common allergens.
• Total IgE levels were also measured.

Main Results:

• A significant concordance (64.1%) and conflict (35.9%) were observed among the three testing methods.
• Positive prick tests were generally confirmed by intradermal reactions.
• Negative prick and intradermal tests were less likely to be confirmed by specific IgE results.
• Intradermal reactions were frequently positive for mites but often unconfirmed by other methods.
• Serum specific IgE levels were higher in patients with positive prick and intradermal tests.

Conclusions:

• The skin prick test is recommended as the initial routine diagnostic test for respiratory allergies.
• Intradermal testing should be considered when prick tests are negative but clinical history is suggestive.
• If both prick and intradermal tests are negative, specific IgE measurement is less likely to be positive, potentially reducing unnecessary testing.