Predictors of severe and recurrent adult anaphylaxis, and gaps in the cascade of care: a retrospective, single-centre study 2009-2018.

BACKGROUND: Anaphylaxis is a severe, potentially fatal, systemic allergic reaction. Understanding predictors of recurrent and severe anaphylaxis in adults, and identifying gaps in ongoing anaphylaxis care, is needed to minimise its impact. AIMS: To evaluate the risk factors in adults with severe and recurrent anaphylaxis presentations and to evaluate the management of patients in regard to the recommended cascade of care. METHODS: We completed a retrospective audit of adults with confirmed anaphylaxis who presented to an inner-city emergency department from 1 January 2009 through 31 December 2018. Data recorded included demographics, background history, medication use, severity, co-factors, triggers, management, discharge disposition and referral for follow-up. Data were managed in REDCap and analysed using Stata. Associations were assessed through odds ratios (ORs) and t tests. RESULTS: Six hundred sixteen individuals had 689 episodes of anaphylaxis over the audit period. Age over 65 (OR: 5.4 (95% confidence interval, CI: 2.3-13.2), P < 0.0001) and history of asthma (OR: 1.6 (95% CI: 1.03-2.5), P = 0.03) were independent risk factors for severe anaphylaxis. History of food allergy (P < 0.001) and food as the trigger were associated with recurrent presentations (OR: 2.1, 95% CI: 1.1-3.9, P = 0.01). Only 19% of patients met the recommended cascade of care, with post-adrenaline monitoring and recommending follow-up with an allergy specialist demonstrating the largest gaps. There were increased presentations with time but no difference in triggers or severity. CONCLUSIONS: Increased age and asthma were identified as risk factors for severe presentations. History of food allergy was a risk factor for recurrent presentations. Further research is needed on the gaps in care for adults with anaphylaxis to identify the reasons why, so we can better care for these patients.