Diagnosis
Oral Food Challenge
The diagnostic gold standard — a supervised, graded feeding of the suspected allergen to confirm or exclude a true allergy and define safe thresholds, with full resuscitation facilities on hand.
Why is the OFC considered the gold standard
Skin and blood tests - unless negative or strongly positive - only show a state of IgE sensitisation, not whether a reaction will always occur. A supervised oral food challenge is able to answer this question. An OFC gradually introduces the food under close monitoring, giving a definitive answer which facilitates a safe diet, bespoke emergency plan, and the dicussion of treatment options.
When we recommend it
To confirm or exclude an allergy where tests are equivocal, to check whether a child has outgrown an allergy, and to define safe thresholds before or during oral immunotherapy.
Safety
Challenges are conducted by nurses and Dr's experienced in food allergy and anaphylaxis management, with immediate access to resuscitation pathways. London Allergy Consultants undertake low risk challenges and supervised feeds in clinic; where the risk is deemed higher, we perform most of the higher risk challenges at the Allergy Centre of Excellence, we also refer to the Evelina Children's Hospital and the Portland Hospital for Women and Children.
Logistics
The challenges can be done as supervised feeds (single, or 2-3 doses, in clinic) with Dr's Du Toit and Foong, or as higher risk procedures in the Allergy Centre of Excellence (incrimental slower dosing).
We also undertake clinical research trails where challenges are undertaken in ACE which are doublebinded and done over two days.