They do. These incidences are rare, but documented, and researched. https://www.scientificamerican.com/article/when-peanut-allergy-comes-from-a-blood-transfusi

They do. These incidences are rare, but documented, and researched. https://www.scientificamerican.com/article/when-peanut-allergy-comes-from-a-blood-transfusion/ https://www.scientificamerican.com/article/when-peanut-aller... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4562830/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4562830/ It looks like the allergy isn't permanent though.