What should you know about hypertensive anaphylaxis?

Anaphylaxis is a rapid, severe allergic reaction that can affect breathing, the throat, skin, circulation and digestion. Blood pressure may be high early in an episode, may change later, or may not reflect how quickly the reaction is progressing. Wheezing, throat tightness, swelling of the lips or tongue, widespread hives, repeated vomiting, sudden dizziness or collapse after an exposure are warning signs. Food allergy, medicines and insect stings are possible triggers, but the trigger is not always known.

Use an adrenaline auto-injector immediately if one has been prescribed for the person, following its instructions, and call emergency services. Say that anaphylaxis is suspected. Keep the person lying down with legs raised if tolerated; let them sit with legs out if breathing is difficult, and do not let them stand or walk. A second prescribed injector may be needed if symptoms continue or return, according to the emergency plan. Do not rely on an antihistamine or a blood pressure reading as the main treatment.

Seek emergency help immediately for any combination of breathing difficulty, throat or tongue swelling, wheezing, faintness, collapse or rapidly spreading allergic symptoms. Hospital observation may be needed because symptoms can return after initial improvement. Anyone who has had suspected anaphylaxis should receive medical assessment, even if the reaction settles.

Ask what triggered the reaction, how to use an auto-injector, whether you need allergy testing, and how to make an emergency plan for home, school or work.