Other: In-Clinic Food Challenge (Control Arm)

Participants randomised to the control arm will undergo a standard in-clinic oral food challenge conducted under direct medical supervision. The protocol used is derived from the PRACTALL consensus and ASCIA position statements and involves administration of increasing doses of the implicated food at 20-30 minute intervals over a 2-3 hour period. Observation continues for 1-2 hours post final dose. The challenge is performed in a hospital outpatient clinic equipped for anaphylaxis management. The food challenged is selected by the participant from their eligible food allergy labels.

Experimental: Home-Based Food Challenge (Intervention Arm)

Participants randomised to the intervention arm will undertake a structured home-based oral food challenge over five consecutive days. This begins with an initial supervised dose administered in clinic under medical observation (60-minute monitoring period). Participants will then self-administer increasing doses of the implicated food at home each subsequent day using a standardised protocol adapted from PRACTALL and ASCIA guidelines. Dose intervals are 24 hours to reduce risk of cumulative reactions. Participants are provided with written instructions, emergency action plans, and have daily phone follow-up with allergy nursing staff during the challenge. The challenge food is selected by the participant from their eligible food allergy labels.