Food Challenge at Home or in Medical Practice - the FoodCHOMP Study

This is a pilot, multi-centre, randomised clinical trial evaluating the safety and feasibility of a home-based oral food challenge in adults with low-risk food allergy labels. Eligible participants are aged 18 years or older and have a self-reported food allergy with negative skin prick testing to the implicated food. Participants will be randomised to either a home-based or standard in-clinic food challenge. The primary aim is to determine the safety of home challenges, measured by the rate of immune-mediated adverse events. Secondary aims include feasibility of recruitment and delivery, protocol adherence, quality of life, and food reintroduction outcomes.

Food allergies are highly prevalent and contribute to significant patient anxiety and healthcare utilisation. Many individuals carry food allergy labels without confirmation through diagnostic food challenge, resulting in unnecessary food avoidance. In-clinic food challenges are the current standard for confirming tolerance but are resource-intensive and often delayed. This study evaluates whether selected low-risk adults can safely complete a structured oral food challenge at home.

This is a pilot, multi-centre, randomised controlled trial conducted at two tertiary allergy centres in Victoria, Australia (Austin Health and Royal Melbourne Hospital). Adults referred with a reported food allergy will undergo clinical assessment and skin prick testing. Those with negative skin testing (\<3mm wheal) to the implicated food and meeting other eligibility criteria will be randomised 1:1 to either:

* Intervention: Home-based oral food challenge over five days, beginning with a single supervised dose in-clinic and followed by four incremental doses at home with daily clinical follow-up.
* Control: Standard in-clinic oral food challenge using a protocol derived from PRACTALL and ASCIA guidelines.

The primary outcome is the proportion of participants experiencing an immune-mediated adverse event during food challenge. Secondary outcomes include feasibility metrics (eligibility, recruitment, delivery), non-immune mediated adverse events, protocol adherence, quality of life (measured by FAQLQ-12), time to challenge, and real-world food reintroduction.

The study will enrol 120 participants (60 per arm). Outcomes will inform the design of a future non-inferiority trial and may support integration of home challenges into routine practice for selected patients.

Eligibility Criteria:
Inclusion Criteria:

1. Negative (\<3mm) fresh or extract skin testing to the food implicated within their allergy label
2. Aged greater than 18 years

Exclusion Criteria:

* Evidence of prior sensitisation to challenge food 0 Defined as previously positive skin testing or allergen specific IgEs if available
* Pregnancy
* Patients with poorly controlled asthma - defined as an ACQ5 scores \>1 at the time of enrolment
* Patients with a history of food reactions that is not-consistent with an IgE mediated process; i.e. exclusively gastrointestinal symptoms, FPIES
* Patients with a clear history of food-dependent exercise induced anaphylaxis
* Patients on a concurrent medication which may influence the outcome of the challenge;
* Antihistamine therapy; Patients receiving more than stress dose steroids (i.e. \> 50mg QID hydrocortisone \[or steroid equivalent\]); Omalizumab
* Any other illness that, in the investigator's judgement, will substantially increase the risk associated with subject's participation in this study