Thank you for your inquiry.
Here is a site that contains a list of all the contents of every flu vaccine. From this site, you will see that there are many possibilities for anaphylactic reactions in terms of the contents of each vaccine (which can differ). The information is of course too complex to copy and paste in this response. I would advise you therefore to look at each of the vaccines for the contents yourself. As noted, you will find multiple ingredients that could possible cause reactions including polysorbate, gentamicin, neomycin, polymyxin, et cetera, in different vaccines.
There is a very small amount of gelatin (hydrolyzed porcine, 200 mg) in FluMist and 0.05% gelatin in Fluzone, according to this site.
I do not know what vaccine your patient was given, but you might consider testing to a vaccine in this list which contains different contents.
Thank you again for your inquiry and we hope this response is helpful to you.
Phil Lieberman, M.D.