The best replacement for anaphylaxis is anaphylactoid.

The best alternatives to anaphylaxis are rated as following:
★★★★★  anaphylactoid
★★★★★  anaphylactic shock
★★★★  asthma
★★★  angioedema
★★★  anaphylactoid reaction
★★★  panic attack
★★  vasovagal
★★  septic shock
★★  mild allergic reaction
★★  allergic reaction
★★  sepsis
★★  syncope
★★  anaphylactic
★  systemic reaction
★  anaphylactoid reactions
★  allergy
★  atopy
  allergic
  severe allergic reaction
  fainting
  urticaria

Your alternative for anaphylaxis is not listed? Suggest!
Speaking about anaphylaxis, one probably shouldn't forget about hives.

Other search terms related to anaphylaxis and their ratings are:
★★★★★ hives
★ allergy
epinephrine
You have in mind a companion for anaphylaxis and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of anaphylaxis in all years. Click on graph for more.
anaphylaxis
anaphylactoid
anaphylactic shock