Why have a challenge?
A challenge is the best way to establish whether your child is allergic to a food or drug. Your doctor or nurse will have decided your child should have a challenge based on what you have told them, skin tests and/or blood tests, with usually a high chance of your child being able to tolerate the food or drug. This may help your child to lead a more normal life, with fewer restrictions and without fear of reacting to that specific food or drug.
How is a challenge performed?
At each stage of food or drug administration, your child is carefully checked for signs of an allergic reaction. Once all of the doses have been eaten you will need to stay on the ward for at least two hours to ensure there is no delayed reaction. If a reaction occurs, your child will be monitored for around 2-4 hours; a few children may require admission to the ward.
Before challenge
Your child must be well, with no cough, cold or recent infections for at least one to two weeks before the challenge. If they have asthma, hay fever or eczema this must be well controlled and stable.
Medications your child is taking before a challenge
Antihistamines
Your child may be using prescribed medications called antihistamines, such as Piriton, Clarityn, Cetirizine or Zirtek. Anti-histamines are also present in some cough medicines so please check!
These should be stopped five days before admission as they can mask the severity of symptoms of an allergic reaction during the challenge.
Asthma medication
Preventer: your child should continue to use their regular preventative asthma inhalers (brown, purple, red or orange). You must not stop them before the challenge.
Reliever: Blue inhalers, Salbutamol or Symbicort
If your child is wheezy, coughs or has exercise-related asthma symptoms then this inhaler should be given as normal. However, if your child is using their blue inhaler or extra puffs of their Symbicort inhaler more frequently than normal in the two weeks prior to the challenge, please telephone the Paediatric Asthma/Allergy team on 01895 279721 to let them know and to discuss treatment options.
Our Paediatric Asthma/Allergy nursing team will try to call you two weeks before the challenge to ensure your child's asthma is well controlled before the challenge. If for some reason you do not speak to them, and your child has had symptoms of cough and wheeze during the preceding 2-3 weeks, it is unlikely that we can proceed with the challenge as it would not be safe to do so – please contact the team by calling 01895 279721.
What are the possible risks?
There is a potential risk of your child having an allergic reaction to the food or drug being tested, which is why we perform this in hospital and not at home. Your child will remain under close observation of a nurse, with a doctor available if needed. If your child experiences a reaction, the challenge will be stopped and medication will be given. Medication administered will be dependent on your child’s symptoms but may include an antihistamine such as Cetirizine and Salbutamol (if asthmatic). In the case of a more severe reaction, an adrenaline auto-injector (e.g. Epipen) will be administered.
Preparing your child
Preparing your child for their hospital visit will help them understand what is happening and can improve your child’s willingness to cooperate on the day. You may wish to bring some familiar toys or books on the day to help your child feel at ease. If you feel your child might be very reluctant to try the food on the challenge day, or afterwards on a regular basis, then please discuss this with the Allergy Team before coming into hospital.
Lunch will be provided for your child on the day but please feel free to bring your own lunch or snacks with you. It is also a good idea to bring other foods they like, so that we can use it to disguise the taste of the food being challenged, if needed. You will need to stay with your child at all times during the challenge, so you may also want to bring some food for yourself.
The challenge procedure
- General assessment: Your child will be assigned a nurse who will explain what the challenge involves and look after you and your child for the whole day.
Generally, the following things will happen:
a nurse will weigh your child and take their temperature, pulse and blood pressure. The nurse will continue to monitor these throughout the day
the ward doctor or nurse specialist will check your child to make sure they are fit for the challenge
they will also answer any questions you may have.
After the challenge
If your child has not reacted, after a successful two-hour observation period they can be discharged home.
Delayed reactions with rashes and tummy upset are possible for up to 48 hours. If this occurs, please contact the Asthma/Allergy Team on 01895 279721 or email thh-tr.PaedAllergy@nhs.net for advice. Please send pictures of any rashes and follow your child's original allergy management plan.
For food challenges, if no reaction occurs after 48 hours your child is no longer allergic and must include the food in their diet regularly (at least twice a week).
If your child reacts at the challenge, they will need to continue to avoid the food or drug.
The Asthma/Allergy Team will write to your GP with the outcome of the challenge and update their management plan as necessary.
Other practicalities
Our service runs Monday-Friday and you will be allocated either a 7.45am or 8am slot. Please arrive on time as arriving late may lead to the challenge not going ahead for safety reasons, as a nurse is allocated to each challenge and this may be compromised.
Please note only one parent or guardian is allowed to stay with the child during the challenge as we have limited space. For children or parents who require additional support, please discuss with the Asthma/Allergy Team on 01895 279721.
We can only allocate two challenges a day. Because of the high demand for challenges, if you cancel your child’s appointment on two occasions or your child is not brought on the day of their appointment, they will be discharged from our service.