What should you know about drug allergy hives?

Hives are raised, itchy welts that can appear suddenly and move around the skin. A medicine can trigger them soon after a dose, but infections, foods and other exposures can also cause hives. The appearance alone cannot confirm the cause. Note the medicine name, dose, timing, other medicines and how the rash changed.

A suspected allergy should be recorded clearly in your medical notes. Do not test the medicine again at home. A clinician may decide that another treatment is safer or that specialist assessment is needed.

Contact a GP Consultation service or prescriber promptly for advice about the suspected medicine. Keep the packet or a photograph of its label, and list any non-prescription products, supplements and recent medicines. Avoid sharing the medicine or using leftover doses.

A cool compress and loose clothing may reduce irritation while you wait. Take only an antihistamine or other treatment if a pharmacist or clinician says it is suitable for you, particularly if you are pregnant or take other medicines.

Call emergency services immediately for swelling of the lips, tongue or throat, trouble breathing, wheezing, faintness, confusion or rapidly worsening symptoms. These can be signs of Anaphylaxis. Do not drive yourself if breathing or circulation is affected.

Ask whether the medicine should be avoided, which alternatives are suitable, how the allergy should be documented and whether Allergy Testing could help. Confirm what to do if hives return.