What’s in a label? Can use of a questionnaire-based tool identify patients that may benefit from antimicrobial allergy ‘de-labelling’

Being labelled as “allergic” to an antimicrobial (commonly penicillins) can lead to worse clinical outcomes and increase antimicrobial resistance. Unclear or inappropriate allergy documentation contributes to this issue so clarifying “allergy” status is important to optimise clinical outcomes.

Methods

The study was conducted at St Thomas’ Hospital, a large teaching hospital in London. An antimicrobial allergy assessment process, consisting of a researcher-developed and administered questionnaire, a review of patient medical records and categorisation of the drug allergy ‘label’, was applied to eligible patients from selected wards. Recommendations for allergy ‘de-labelling’ and referrals were given based on patient categorisation.

Sixty assessments were completed during the study. Six patients (10%) were identified as unlikely to have a true allergy and could potentially be ‘de-labelled’. A further thirty-seven patients (61.7%) were identified as eligible for allergy referral and testing. The allergy ‘labels’ of twenty-seven patients (45%) led to them receiving second-line antibiotic therapy. Twenty-two patients (34.7%) had inconsistencies in their allergy documentation across the 3 main electronic clinical systems.

This study demonstrated that the use of a simple, standardized, pharmacy-led approach to antimicrobial allergy assessment could lead to some patients being 'de-labelled' outside of specialist allergy settings. The implementation of this approach could immediately bring about improvements in antimicrobial usage and patient outcome.