What is the correct spacing required for a scratch allergy test?

For scratch allergy testing, the correct spacing between the testing sites is crucial to ensure accurate results and to minimize cross-reactivity between allergens. The recommended spacing of 1 to 1 1/2 inches allows enough distance between the individual scratch sites so that the reactions to different allergens do not overlap. This spacing also enables clear observation of each reaction, which is important for interpreting the results effectively.

In addition, having the sites placed too closely could lead to misinterpretation of the reactions, as a combined response might not accurately reflect an individual’s sensitivity to each specific allergen being tested. The chosen spacing is standard practice in allergy testing protocols to maintain the integrity and reliability of the results.