Food and Drug Reactions and Anaphylaxis
Epidemiology of anaphylaxis among children and adolescents enrolled in a health maintenance organization

https://doi.org/10.1016/j.jaci.2003.11.033Get rights and content

Abstract

Background

There is little information about the incidence of anaphylaxis from all causes.

Objective

The objects of this study were (1) to estimate the incidence of anaphylaxis; (2) to explore the range of diagnoses attributed to an anaphylactic episode; and (3) to describe the clinical features of anaphylaxis.

Methods

The study population consisted of children and adolescents enrolled at a health maintenance organization. We identified potential episodes of anaphylaxis occurring between 1991 and 1997 from automated databases and reviewed the medical record to confirm the diagnosis. We reviewed all diagnoses specific for anaphylaxis (eg, ICD-9 995.0, anaphylactic shock) and sampled from among other related diagnoses (eg, ICD-9 995.3, allergy unspecified). Estimation of the incidence of provider-diagnosed anaphylaxis was based on cases confirmed from among the specific diagnosis codes. Description of the clinical features of anaphylaxis involved all confirmed cases regardless of diagnosis.

Results

We identified 67 episodes of anaphylaxis among children with diagnosis codes specific for anaphylaxis (10.5 episodes per 100,000 person-years). There was no increase in incidence over time. Review of samples of diagnoses not specific for anaphylaxis yielded an additional 18 episodes. Among all identified episodes (n = 85), mucocutaneous and respiratory manifestations were the most common. Seventy-one percent of episodes were treated in the emergency department. Nine episodes (11%) resulted in hospitalization.

Conclusions

The incidence of anaphylaxis did not increase during these years. A majority of episodes were treated in the emergency department. Anaphylaxis in this population was frequently diagnosed as another related condition, and the basis and implications of diagnostic practices in this disorder warrant further exploration.

Section snippets

Study population

The study was based at Group Health Cooperative, a health maintenance organization (HMO) based in western Washington State. The study population consisted of the 229,422 children and adolescents under the age of 18 years enrolled at Group Health Cooperative for any duration between March 1, 1991, and December 31, 1997.

Definition of anaphylaxis

Our algorithm for assessing anaphylaxis (Fig 1) has been described previously.9 The decision to incorporate treatment was based on the observation that prompt treatment of an

Results

Of 781 diagnoses selected for chart review, 25 were excluded because of missing chart information. In addition, 3 duplicate diagnoses were excluded (the episode received more than one diagnosis of interest and appeared more than once in Table I). This left 753 diagnoses for review.

The code with the highest positive predictive value (PPV) for anaphylaxis was 995.0 (anaphylactic shock); approximately 55% of these visits were confirmed as “probable” or “possible” anaphylaxis (Table II). The code

Discussion

We have described the incidence and clinical characteristics of anaphylaxis in a large population of child and adolescent HMO enrollees. A previous study of anaphylaxis from all causes in a large general population was conducted by Yocum et al, who described the underlying causes of anaphylaxis in Olmsted County, Minnesota, from 1983 through 1987.2 In that study, which considered a broad range of diagnoses, 154 episodes of anaphylaxis occurred among 133 residents. The occurrence rate (which

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  • Cited by (0)

    This study was supported by contract 200-0957 (the Vaccine Safety Datalink project) with the Centers for Disease Control and Prevention and the American Association of Health Plans (AAHP). The findings and conclusions of this study do not necessarily represent the views or policies of the Department of Health and Human Services or AAHP.

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