Incidence, clinical features and management of acute allergic reactions: the experience of a single, Italian Emergency Department

OBJECTIVES: Few data on the incidence, aetiology, clinical features and management of patients with acute allergic reactions presenting to the Emergency Department are currently available. The aim of the study was to report the annual experience of a single Italian adult Emergency Department about anaphylaxis. PATIENTS AND METHODS: This is a retrospective, case-based study of adult patients attending the Emergency Department in Alessandria, Italy, during the years 2009-2010. We evaluated the medical records of patients satisfying diagnostic codes involving acute allergic reactions. Incidence, demographic data, causative agents, clinical features, management and outcome were reported. RESULTS: 390 patients with acute allergic reactions were evaluated during the year, corresponding to 0.7% of all Emergency Department visits. Causative agents were recognized in 55.1% of patients and more commonly included drugs (26.9%), insects (14.8%) and foods (8.9%). Cutaneous features were the single most common clinical presentation although two or more clinical features were frequently reported (17.7%). Anaphylaxis was diagnosed in 4.6% of patients. After therapy and a period of monitoring, 92.8% of patients were discharged directly from the Emergency Department, 7.0% were admitted and one patient died, corresponding to a fatality rate of 0.2%. CONCLUSIONS: Acute allergic reactions are common diseases referring to our Emergency Department. In the half of cases a precipitant agent was identified and cutaneous and/or mucosal changes were often the first feature. Most patients were definitely treated and discharged but about 7.0% of patients required hospitalisation. Observation Unit and Intermediate Care Unit were essential for clinical management of these patients.