D1.17 - Service Evaluation of patients with Suspected Allergic Reactions presenting to the Emergency Department of a tertiary Irish teaching hospital

Anaphylaxis is a potentially life-threatening multisystem allergic reaction requiring immediate recognition and intervention. Emergency department presentations are increasing. This service evaluation was conducted in the emergency department (ED) of a tertiary Irish teaching hospital which until recently had no on-site immunology service. Therefore variability in practice was anticipated, with serum tryptase measurement expected to be rare despite European Academy of Allergy and Clinical Immunology guidelines recommending its use. 

This service evaluation aimed to establish baseline practice in the assessment, investigation, and follow-up of patients presenting to the ED with suspected allergic reactions. Findings will inform the development of a standardised ED proforma and pathway.

Two interlinked retrospective service evaluations were undertaken: (1) ED presentations with suspected allergic reactions, and (2) serum tryptase requesting practices, including timing, repeat sampling, and referral. ED presentations between 01/01/2025 and 30/06/2025 were reviewed and 126 patients met inclusion criteria, with preliminary analysis available for 50 of these. In parallel, ED serum tryptase requests from 01/01/2025 to 30/09/2025 were analysed.

Of the 50 patients analysed as part of the first evaluation, most were female (n=34) and aged 21-40 (n=34). Most were managed and discharged directly from the ED; 29 received treatment in ED, while four required hospital admission. Serum tryptase testing was performed in six patients with just one having a repeat sample sent.

The second evaluation identified 32 ED serum tryptase requests between January and September 2025. Initial sample timing was highly variable, ranging from within five minutes to over 48 hours after admission. Documentation of referral was inconsistent with just seven (22%) being directly referred to allergy clinic.

Baseline service evaluation identified clear gaps in diagnostic support and follow-up for patients presenting with suspected allergic reactions, particularly regarding serum tryptase testing and referral pathways. These findings directly informed the development of a revised ED anaphylaxis pathway with a standardised proforma and clinical prompts designed to support appropriate investigation and follow-up including timely initial and repeat serum tryptase samples.