Skin tests in comparison with other diagnostic methods

In general there are high correlations between positive results to properly performed epicutaneous skin tests and the results of eye, nose, or lung challenges with the homologous allergen. The results of epicutaneous skin tests are also highly correlated with the results of in vitro tests and clinical histories. These correlations between the tests and challenges are highest when potent, well-characterized allergen extracts are used. For most common allergens, the results of intracutaneous skin testing add little if anything to correlations between skin test results and the results of challenges or to predicting clinical histories. The extra sensitivity of intracutaneous skin tests may be valuable when high potency extracts are not available or when the risk of a falsely negative test is high, as with drug or insect venom allergies; however, this commonly stated assumption rarely has been examined critically. All physicians caring for patients with histories suggestive of allergic disorders must be keenly aware of the strengths and limitations of all available testing methods.