Can the Fishbane reaction happen with an initial test dose of Low molecular weight iron dextran (infed)? i.e do you need prior sensitization or is the test dose 'not enough' to cause the reaction?

Recently had a patient immediately start to get flushed, diaphoretic, feeling SOB, and was hypotensive to 90/50 after the test dose of infed and then had a few episodes of emesis. Unsure if exceedingly rare anaphylaxis vs Fishbane?