Gastrointestinal symptoms of anaphylaxis: what to know

Anaphylaxis is a severe, whole-body allergic reaction. Digestive symptoms may include sudden severe abdominal cramps, repeated vomiting or diarrhoea. They can occur with hives, flushing, swelling of the lips or tongue, throat tightness, hoarse voice, dizziness, collapse or breathing difficulty such as Wheezing. Symptoms may appear soon after a food, medicine, insect sting or other trigger, but the absence of a skin rash does not rule out an emergency. Gastrointestinal upset alone has many causes; the timing and combination of symptoms matter.

If anaphylaxis is possible, use the person’s prescribed adrenaline auto-injector immediately according to its instructions, then call emergency services. Do not make the person stand or walk. Lay them flat with legs raised if breathing is comfortable; let them sit up if breathing is difficult, and place them on their side if vomiting or unconscious but breathing. A second injector may be needed if symptoms do not improve and emergency guidance advises it. Do not rely on antihistamines alone for airway or circulation symptoms.

Treat sudden digestive symptoms after a suspected allergen as an emergency when they occur with breathing trouble, throat or tongue swelling, faintness, confusion, pale or clammy skin, weak pulse or collapse. Call for help even if the person seems better after adrenaline because symptoms can return. Anaphylaxis Emergency Treatment should be reviewed after the event, and the person should receive observation and a follow-up plan.

Ask what trigger is most likely, whether Allergy Testing is appropriate, how to use an auto-injector, when a second dose is needed, and how to create an avoidance and emergency plan. Tell the clinician exactly what was eaten, taken or encountered and how quickly each symptom began.