Oral Challenge Test (OCT) - the preparing

What is a challenge test?

An oral challenge test is a medical procedure in which food is eaten in gradual doses under the supervision of a doctor.

Oral Challenge Test (OCT) is the most reliable method for diagnosing food allergies. A food challenge is used to determine the presence or progression of a food allergy — to find out if someone really has a food allergy when the history and results of an allergy test are unclear.

How to prepare for an oral challenge test

You/your child should be healthy on the day of the test. Please call your doctor to discuss any symptoms of illness, asthma or allergies. You may need to postpone the food challenge if you/your child have been sick for a week (for example, with a fever, infection or taking antibiotics). Your/your child's asthma, eczema or allergic rhinitis symptoms are poorly controlled or have worsened in the week before the challenge.

Treatment recommendations

Stop all antihistamines 3-10 days before challenge as directed by your doctor. Other medications may be discontinued as directed by your doctor.

Continue to use all asthma preventer/treater steroid inhalers and nasal steroid sprays (fluticasone, beclomethasone, mometasone). If your asthma preventer inhaler contains salmeterol or formoterol, do not use this inhaler for 8 hours before challenge. Use a reliever inhaler (salbutamol) if needed to relieve symptoms, then notify your doctor.

Never avoid treating your allergies or asthma with rescue medications because an AKI is approaching. If you/your child needs to use a reliever inhaler, antihistamine, or even epinephrine, please use the medication and then call your doctor to discuss the symptoms if the test needs to be postponed.

If you have any questions about a specific drug, ask your doctor.

Food before the test

Your child should not eat anything for at least 4 hours before the challenge. Infants and young children can be given a light meal 2 hours before the test.

What to bring to the food test

Your doctor will provide detailed information about the specific foods you need to bring.

Bring something to entertain yourself/your child during the visit.

Special considerations for children

Prepare your child for the food test by explaining the procedure.

Tell him or her that the food will be eaten in the doctor’s office and that the doctors and nurses will ensure their safety. Emphasize that your child can bring toys, games, books.

Bring anything that might make it easier for your child to eat the new food (favorite plates, cups, spoons, prizes, etc.).

How long does an oral challenge test last?

Plan on staying in the hospital for 12 to 24 hours; this depends on your child's reaction to the food. Your stay may be longer or shorter, depending on your history, the type of food allergy, and what happens during the test. If you/your child is asymptomatic, you/your child will be monitored in the ward for 4 to 5 hours after the last dose to rule out a possible biphasic anaphylactic reaction.

If you/your child has a reaction during the test, the monitoring time will vary. If the reaction requires treatment with epinephrine, you/your child will need to be monitored for several hours after the epinephrine is given. If the reaction is significant or severe, there is a small chance that you/your child will need to be taken to the emergency department for further monitoring or additional treatment. Please have a backup plan in case you have to stay for the entire day.