A drug challenge is used to determine if your child is allergic to a particular medicine. It is usually started by a doctor in hospital and may be continued at home, particularly for antibiotics.
Your child will have experienced symptoms, such as a rash, while taking the drug. It is possible that the symptoms were not due to the medicine but rather an infection or other illness. If so, it would be good to know if your child could take the drug, should they need to in the future.
A drug challenge will determine whether your child is truly allergic to a medicine. If your child does not develop any allergic symptoms, then we can advise that they can take it in the future, if needed.
Your child may have an allergic reaction to the drug, which is why the test is done in hospital. The challenge will be stopped if your child has an allergic reaction, and the necessary treatment given.
You may choose for your child not to have a drug challenge and continue to avoid the drug. A drug challenge is the only safe and sure way of finding out if your child is allergic to the drug or not.
Explain to your child what the drug challenge will involve. Always give truthful, factual information. You may bring any favourite toys or books on the day. Your child will be able to have a snack and drink during the challenge.
Oral antihistamines such as Piriton must be stopped five days before the challenge. Nasal sprays containing an antihistamine may be continued.
Your child should continue to take all their asthma inhalers. If your child has needed to use their blue inhaler more often than usual in the last two weeks, then you should contact the Allergy team to discuss whether your child is well enough to have the challenge.
Your child should not have taken steroid tablets within two weeks of the drug challenge day. It is fine to continue their steroid nose spray, steroid inhaler or steroid creams as these will not affect the challenge outcome.
A doctor or nurse will make sure that your child is fit and well to have the challenge. You will then be asked to sign a consent form for the challenge. The final decision to have the challenge is up to you and your child.
Your child will be given a small dose of the medicine, usually starting with a tenth of the usual dose. If there is no reaction after 30 – 60 minutes larger doses will be given to try. Your child will then be observed for another hour and sometimes longer. A drug challenge usually takes 2 to 4 hours.
If your child has not reacted to the antibiotic given to them while on the Medical Day Unit, they will be asked to continue the antibiotic for a further five days at home in order to make sure that they don’t get a rash or other reaction after taking a longer course of the medicine.
If your child shows signs of a mild allergic reaction such as a rash, then you should STOPthe antibiotic and give an antihistamine if it is indicated. Please take photos of the rash. Do not give any more doses, but contact the Allergy team to report the reaction.
If the reaction is more severe, and involves symptoms such as coughing, wheezing, breathlessness or collapse, then you should call 999 for an ambulance immediately.
If your child completes the course of antibiotics, then please contact the Allergy team to let us know that there was no reaction. We will then inform your GP that your child is NOT allergic to the medicine and it can be prescribed if needed in the future.