Thank you for your inquiry.
I think it is highly unlikely that your patient reacted to penicillium roqueforti for the following reasons:
1. The U.S. Environmental Protection Agency Biotechnology Program Report under the Toxic Substances Control Act has not found any cases of food allergy of any sort, including anaphylaxis, to penicillium roqueforti. In fact, there was only possibly one adverse event with an underlying immunologic pathophysiology. This occurred in a patient working at a plant manufacturing penicillium roqueforti. The patient developed a cough, shortness of breath, diminished lung functions, and bibasilar crackles with a chest x-ray showing bilateral infiltrates, findings consistent with a hypersensitivity pneumonitis.
2. A literature search also failed to reveal any additional immunological events, specifically IgE-mediated events, to penicillium roqueforti.
3. You stated that your patient had eaten cheese previously, and penicillium roqueforti is found in a number of different cheeses outside of Maytag Blue. These include Roqueforts, Stiltons, and gorgonzolas.
For the reasons mentioned above, it is doubtful that penicillium roqueforti was responsible for your patient’s anaphylactic event.
One thing that you might do, if you are still considering the cheese as the culprit, is to obtain Maytag Blue cheese and do a “prick to prick” skin test with it, employing yourself and possibly other members of your practice or the relative(s) of your patient as controls to make sure that any reaction is not due to an irritant response.
For your interest, here is a statement from the Environment Protection Agency regarding the safety of penicillium rocqueforti.
Thank you again for your inquiry and we hope this response is helpful to you.
Phil Lieberman, M.D.