Anaphylaxis and acute allergic reactions in pharmacy

Pharmacy teams may encounter allergic reactions after vaccination, during medicines advice, following OTC recommendations, with injected medicines, or from exposure to a known allergen on the premises. Most mild reactions are not anaphylaxis, but severe reactions can progress rapidly and must be treated as emergencies.

When to suspect anaphylaxis

Resuscitation Council UK advises suspecting anaphylaxis when there are airway, breathing, or circulation problems, with or without skin or gut symptoms. Clues include:

• throat tightness, tongue swelling, hoarse voice, or noisy breathing
• wheeze, breathlessness, persistent cough, or rapidly worsening breathing difficulty
• flushing, hives, widespread rash, or swelling of lips and face
• cold clammy skin, faintness, collapse, or sudden confusion
• abdominal pain, vomiting, or diarrhoea after likely allergen exposure

Immediate priorities

• Call 999: say "suspected anaphylaxis".
• Remove the trigger if possible: for example stop the vaccine or medicine administration if still in progress.
• Position the patient safely: if breathing is difficult they may prefer to sit up with legs extended, but people with low blood pressure should lie flat. Do not make them stand or walk.
• Give IM adrenaline promptly if trained and locally equipped to do so: repeat after 5 minutes if symptoms persist, following local guidance and the product or service protocol.
• Monitor closely: be ready to move to CPR if the person becomes unresponsive and is not breathing normally.

If oxygen is available in your setting and you are trained to use it, follow local protocol. Do not delay adrenaline or 999 calling while looking for oxygen.

Mild rash alone is not anaphylaxis. Once airway, breathing, or circulation are affected, stop debating and treat it as a time-critical emergency.

Vaccination services and emergency arrangements