AllergyNotes links to a case description in the Journal of Investigational Allergology and Clinical Immunology of something never reported before (according to the authors, at least): a sexually transmitted allergic reaction to Brazil nuts.
Allergic reactions due kisses have been reported in the media and medical literature before.
Dangerous Liaison: Sexually Transmitted Allergic Reaction to Brazil Nuts. J Investig Allergol Clin Immunol 2007; Vol. 17(3): 189-191.
Image source: Mixed nuts, Wikipedia, public domain.