How can we determine who is truly allergic? The explanation of skin testing and its utility in several medical settings
Skin testing should include both major and minor determinant to improve sensitivity.
A minority of patients will react to minor determinant alone and these individuals have an increased risk of IgE-mediated anaphylaxis.
Currently, in the US there is no commercial source for the minor determinant. Often fresh PCN G is used for this purpose.
In recent months, there has also been some manufacturing difficulty with the major determinant.