Anaphylactic shock is the most severe form of anaphylaxis, an allergic reaction to a trigger substance such as a food or a drug. Symptoms include respiratory and cardiovascular distress.
In 2373, The Doctor claims that Lieutenant Torres is suffering from delayed anaphylactic shock caused by something she ate when she is found unconscious in Sickbay. In order to fool Captain Janeway and Lieutenant Commander Tuvok, he used cateline to induce Torres into a simulated anaphylactic shock. (VOY: "Darkling")
In 2375, a cytoplasmic lifeform that had attached itself to B'Elanna Torres entered anaphylactic shock when the Doctor and the Crell Moset hologram removed it. The Doctor was able to stabilize its condition by administering stenophyl. (VOY: "Nothing Human")