Jiaci

Epidemiology of Anaphylaxis in French Emergency Departments

J Investig Allergol Clin Immunol 2019; Vol. 29(5): 357-364

doi: 10.18176/jiaci.0348

and recent publications show that it is not as uncommon a

condition as previously thought. However, most publications

to date consider degrees of severity of anaphylaxis, and the

severe forms may still well be considered rare diseases [17].

In the present study, we demonstrated that anaphylaxis was

responsible for 0.16% of ED admissions, with an incidence

estimated at 34 per 100 000 person-years.

Although injectable epinephrine is currently listed

in the WHO list of essential drugs for the treatment of

anaphylaxis, our findings were remarkable in that it was

rarely prescribed, even in severe cases [18]. This finding

is consistent with most recently published data in the

field [2-10]. Additionally, a relevant number of patients

were hospitalized or kept under observation for a shorter

period than recommended [15].

In contrast to most international recommendations [14],

we observed that intravenous epinephrine was administered

very frequently, despite being responsible for serious

complications such as acute pulmonary edema, arrhythmia,

and acute coronary events. In addition, we found a reduced

proportion of referral to allergists and lack of prescription

of epinephrine autoinjectors. We believe that these findings

may be associated with uncertainty among physicians

about the diagnosis of anaphylaxis, which was defined

based on anaphylaxis classed as indirect according to the

ICD-10

codes. The recent recognition of allergy as a full

specialty paves the way for bilateral collaboration with other

specialties and will enhance management of anaphylactic

patients.

Particularly striking was the number of patients who

presented a second episode of anaphylaxis, even with the

allergological diagnosis. Consequently, greater awareness

is necessary among patients and caregivers in order to avoid

re-exposure to known triggers. Educational efforts will also

help to decrease underrecognition of anaphylaxis by patients,

caregivers, health professionals, health authorities, and

governments. In addition, allergy academies have promoted

training programs and publications in the field [1,14,15,19-22].

Serial serum (or plasma) levels of tryptase should be

collected to guide the diagnosis of anaphylaxis or to exclude

mast cell disorders, which can mimic anaphylaxis. However,

these samples have only been collected in a limited number

of severe reactions, thus indicating the need for a systematic

anaphylaxis action plan. National and international guidelines

have been drafted to fill these gaps [14,23-25].

Underreporting or underestimation of anaphylaxis can

be explained by the difficulty in coding anaphylaxis deaths

under the WHO ICD system. Limited numbers of

ICD-10

codes are considered valid for the morbidity and mortality

of anaphylaxis [8], as demonstrated in patients diagnosed

by direct

ICD-10

codes for anaphylaxis (46 cases) and

indirect anaphylaxis

ICD-10

codes (277 cases) (Figure).

For this reason, we included additional codes related to

manifestations and causes that could resemble or induce

anaphylaxis or even allergic reactions (Table 1). Over the

last 5 years, a strategic international action plan supported

by the Joint Allergy Academies and the WHO [11,17,18,26-

31] was implemented to update the classifications of

allergic conditions for the new edition of the ICD. These

efforts resulted in the construction of the new “Allergic

and hypersensitivity conditions” section in

ICD-11

[28,32],

with a subsection dedicated exclusively to anaphylaxis.

The availability of this new section should enable better

morbidity and mortality statistics to be reported.

Recent international achievements have been accompanied

by the efforts made since 2014 to recognize allergy as a full

academic specialty in France. This will improve the training

of health professionals in the field and support quality

management of allergic patients. Anaphylaxis, as well as other

allergic and hypersensitivity conditions, are systemic disorders

that require a multidisciplinary approach [17]. Recognition of

allergy as a full specialty will strengthen collaboration with

other specialties, thus increasing scientific consistency and

awareness.

Our study is the first to report epidemiological data on

anaphylaxis in French EDs. It highlights regional differences

in the incidence and management of the disease. Although the

diagnosis of anaphylaxis is limited by the retrospective nature

of the study, all cases were clinically validated manually

in order to reduce the number of doubtful cases. Another

known limitation is the number of participating EDs and the

size of the geographic area studied, which may have affected

the epidemiological findings. However, our results confirm

national and international efforts for improved diagnosis and

management of anaphylaxis. Broader studies are required to

increase our knowledge of the epidemiology of anaphylaxis

and to support advances in and the use of new classifications

of allergic and hypersensitivity conditions. We intend to

support the implementation process of

ICD-11

in order to

ensure more accurate and comparable data on the morbidity

of anaphylaxis.

In conclusion, there is an urgent need for improved

public health initiatives on the recognition and treatment

of anaphylaxis. The data presented here are consistent

with the findings of the European Anaphylaxis Registry,

which concludes that despite clear recommendations, only

a small proportion of cases of anaphylaxis are treated with

epinephrine [33]. We believe that the present document flags

key problems, which may be managed in the coming years

through implementation of national and international programs.

Strategies to overcome the main barriers in anaphylaxis care

should be based on bilateral partnership between allergists and

emergency physicians.

Acknowledgments

We are very grateful to Marcelo De Carvalho for his

collaboration and support.

Funding

Pascal Demoly and Luciana Kase Tanno received an

unrestricted Novartis andMEDA/Mylan Pharma grant through

the CHRUM administration.

Conflicts of Interest

The authors declare that they have no conflicts of

interests.

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