Optimising Skin Prick Test Thresholds to Support Safer and More Efficient Hospital‑Based Food Allergen Introduction Pathways

¹King’s College London GKT School of Medical Education, United Kingdom
²NHS Education South London, United Kingdom

^*Corresponding Author: Dr Therese-Mary William, Consultant Paediatrician with Special Interest in Paediatric Allergy , NHS Education South London, United Kingdom

Received Date: August 01, 2026

Published Date: September 10, 2026

Citation: William TM, et al. (2026). Optimising Skin Prick Test Thresholds to Support Safer and More Efficient Hospital‑Based Food Allergen Introduction Pathways. Mathews J Pediatr. 11(2):52.

Copyrights: William TM, et al. © (2026).

ABSTRACT

Introduction: Diagnosis of allergies involves Oral Food Challenges (OFCs) or Supervised Feeds (SFs). However, OFCs are resource‑intensive, requiring 4 to 5 incremental allergen doses over approximately 5 hours. Whereas SFs involve a single dose over 2 hours reducing reliance on OFCs. Therefore, using SFs can shorten hospital waiting lists, ensure patient safety and reduce anxiety for families.

Aim: This quality improvement project (QIP) with prospective data collection aimed to safely increase OFC and SFs thresholds to reduce reliance on OFCs and shorten waiting times, while maintaining patient safety and diagnostic accuracy.

Methods: Two Plan-Do-Study-Act cycles were implemented. Cycle 1 increased skin prick test (SPT) thresholds from ≤2 mm to ≤4 mm for SFs, and from >2-4 mm to >4-5 mm for OFCs within a controlled hospital environment. To ensure patient safety, SPT values above 5 mm were not incorporated into the project’s evaluation. Cycle 2 involves the distribution of an informational poster explaining SPTs, OFCs, and SFs, and the aim of the QIP. Patients with a previous anaphylaxis to the food allergen were excluded from the reclassification. Feedback of the informational poster was collected to assess its impact of the changes.

Results: Raising SPT thresholds increased the mean number of monthly SF appointments from 5.2 to 7.0 (34.6% increase) and a 50.0% reduction in OFCs appointments. Two anaphylaxis events occurred in each group with the old conservative thresholds, indicating that the event was unlikely to be attributable to the revised threshold. All anaphylaxis cases (100%) involved nut allergens. Overall, the revised thresholds did not increase severe reactions. Feedback on the informational poster showed that 90.9% of parents were reminded to avoid antihistamines before their child’s appointment.

Conclusions: Raising SPT thresholds alongside introducing an informational poster have reduced the waiting list pressures and increased number of SFs. Clinic efficiency improved while maintaining patient safety. Given the higher risk profile of nut allergens, additional test including low specific immunoglobulin E (IgE) levels (<0.35 KAU/L) and negative component testing (<0.35 KAU/L) should remain mandatory criteria when selecting SFs rather than OFCs in infants and children with a typical history of allergy. Future studies may standardise SPT and IgE thresholds to improve diagnostic accuracy.

Keywords: Paediatrics, Allergy, Oral Food Challenge, Supervised Feed, Skin Prick Test, Anaphylaxis