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.

Epidemiology and disease burden from allergic disease in Scotland: analyses of national databases.

BACKGROUND: There are ongoing concerns about the quality of care provided to patients with allergic disorders in Scotland, but there are relatively few reliable data on the overall disease burden. We sought to: (1) describe the incidence, prevalence and outcome of allergic disorders; (2) estimate healthcare burden and costs; and (3) investigate ethnic variations in the epidemiology and outcomes from allergic disorders in Scotland. DATA SOURCES: national surveys; primary care data; prescribing and medication data; hospital admissions data and mortality data. RESULTS: Allergic disorders are extremely common in Scotland, affecting about one in three of the population at some time in their lives. Incidence was highest for eczema (10.2 per 1000 registered patients). Over 4% of all GP consultations and 1.5% of hospital admissions were for allergic disorders. There were 100 asthma deaths in 2005 (20 per million people). Direct healthcare costs for allergic disorders were an estimated pound130 million per year, the majority of these being incurred in primary care and related to asthma. CONCLUSIONS: Allergic disorders are common in Scotland and given the very high proportion of children now affected, the high disease burden associated with these conditions is likely to persist for many decades.

Acetaminophen and diphenhydramine premedication for allergic and febrile nonhemolytic transfusion reactions: good prophylaxis or bad practice?

Febrile nonhemolytic and allergic reactions are the most common transfusion reactions, but usually do not cause significant morbidity. In an attempt to prevent these reactions, US physicians prescribe acetaminophen or diphenhydramine premedication before more than 50% of blood component transfusions. Acetaminophen and diphenhydramine are effective therapies for fever and allergy, respectively, so their use in transfusion has some biologic rationale. However, these medications also have potential toxicity, particularly in ill patients, and in the studies performed to date, they have failed to prevent transfusion reactions. Whether the benefits of routine prophylaxis with acetaminophen and diphenhydramine outweigh their risks and cost requires reexamination, particularly in light of the low reaction rates reported at many institutions even when premedication is not prescribed.