What should you know about drug allergy skin rash?

A medicine allergy is an immune reaction to a drug or one of its ingredients. The rash may be red, blotchy, raised, itchy or hive-like, and it can appear soon after a dose or after several doses. Other causes, such as a viral illness or irritation, can look similar, so the appearance alone cannot identify the trigger.

Record the medicine name, strength, dose, start date and time the rash began. Include non-prescription products, injections, supplements and recently stopped medicines.

Contact the prescriber or a pharmacist promptly and describe the rash and any other symptoms. Do not take another dose until a clinician advises you, unless they have already given you a clear plan. Do not restart an old medicine to test whether it caused the reaction.

A clinician may review your history, examine the skin and decide whether an alternative is needed. Keep the suspected medicine and its packaging available. A GP Consultation can help assess the reaction, while Allergy Testing may be considered for selected medicines.

Call emergency services immediately for swelling of the lips, tongue or throat, trouble breathing, wheezing, faintness, confusion or rapidly worsening symptoms. These can signal Anaphylaxis. Seek urgent assessment for blistering, skin peeling, painful skin, mouth or eye sores, or a rash with fever.

Ask which medicine is suspected, whether you should avoid related medicines, what to record as an allergy, and what to do if symptoms return. Ask whether you need a written emergency plan or referral for testing.