Monoclonal antibodies, such as ustekinumab, resemble normal human immunoglobulin. Such molecules are not likely to be irritating to the skin other than due to high concentration causing an osmotic effect. I could not find any report of skin testing for specific-IgE in the literature. There are no preservatives in the product (1).
In summary, I am not aware of a non-irritating concentration of ustekinumab for skin testing. I would suggest using a 1:100 and 1:10 and full-strength concentration (90mg/ ml) for percutaneous and intradermal testing. If an apparent positive result occurs, I suggest testing ‘normal volunteers’, including yourself or other clinical staff. The positive or negative predictive value of such testing is not known.
I hope this information is of help to you and your practice.
All my best.
Dennis K. Ledford, FAAAAI