Cold water and anaphylaxis: what to know

A rapid drop in skin temperature can provoke an allergic-type response in some people. It may cause itchy raised welts, flushing or swelling, and severe reactions can affect the throat, lungs or circulation. Wheezing, hoarse voice, trouble breathing, dizziness or collapse are emergency warning signs. A local cold rash without breathing or circulation symptoms is not the same as anaphylaxis, but it still deserves medical assessment if it recurs.

The trigger may be cold water itself, cold air, or an unrelated exposure such as food. A clinician can help distinguish these possibilities and consider other allergy patterns.

Leave the cold water and call emergency services immediately if there is breathing difficulty, throat swelling, faintness or rapidly spreading symptoms. If an adrenaline auto-injector has been prescribed, use it as instructed and follow the emergency operator's advice. Do not return to the water to test the reaction. Keep the person lying down if faint, unless breathing is easier sitting up, and do not leave them alone.

After recovery, avoid deliberate cold-water exposure until a clinician has assessed the episode. Ask about an emergency plan and whether allergy testing is appropriate.

Anaphylaxis is an emergency: call for help at once for trouble breathing, wheezing, throat or tongue swelling, widespread hives with dizziness, confusion, collapse or blue-grey lips. Symptoms can worsen quickly and may return after initial improvement, so medical observation is needed after emergency treatment. Seek a prompt appointment for repeated cold-triggered hives, swelling or itching even if breathing was unaffected.

Could this have been anaphylaxis or a cold-induced skin reaction? Should I carry an adrenaline auto-injector? What should my avoidance and emergency plan include, and would allergy testing help?