Introduction

This campaign provides data on the use of IgE blood tests as an allergy test.

Practice Points

• Most allergic reactions are immediate hypersensitivity reactions caused by IgE antibodies.
• Common triggers include environmental allergens (pollens, pets, dust mites), food, venom and medications.
• Symptoms occur within minutes to two hours of exposure to the antigen.
• Symptoms of food allergy include cutaneous (e.g. hives), respiratory (e.g. wheeze), gastrointestinal (e.g. vomiting) and cardiovascular (e.g. hypotension).
• Allergy testing includes skin prick testing and serum specific IgE to the given allergen.
• Skin prick testing is more sensitive than specific IgE testing. Specific IgE testing for environmental allergens is typically not necessary.
• Allergy testing for foods may be associated with high rates of false positives, up to 50%.
• Do not perform screening panels (IgE tests) for food allergy without previous consideration for the pertinent medical history (Choosing Wisely Canada).
• Allergy testing should only be ordered if the history is suggestive of an allergic reaction and only to allergens suspected on history.

The Problem

IgE serum specific tests are overused in determining whether or not an allergy is present without clinical indication.

Our Data

This graph indicates the number of IgE tests ordered by test.

Did you know that each IgE test per allergen costs about $20?

Number of Bundles by the Number of Tests Per Bundle

Specific IgE testing should be based on the patient’s clinical history.

Ordering more than three IgE blood tests is likely inappropriate.

Although only 27% of test ordering comprises more than three tests, this amounts to 11,552 tests or 69% of tests.

Number of Tests from Bundles With or Without a General IgE Test by Practicing Specialty

This graph shows test usage by specialty.

The majority of tests are bundled with IgE and serum specific.

Number of Bundles by Number of Tests Per Bundle by Practicing Specialty

This graph shows potentially inappropriate bundling by specialty.

Average Number of Tests Per Bundle by Practicing Specialty

What You Can Do

The majority of allergy testing includes more than three specific IgE tests, which is likely inappropriate

• Look at your personal ordering data: Request your data from Quality of Care NL.
• Choosing Wisely Canada Recommendation:
  • Do not perform screening panels (IgE tests) for allergy without previous consideration often pertinent medical history.
• Specific Ordering
  • Only order allergy testing if the history is suggestive of an allergic reaction and only to allergens suspected on history.