Discussion
Anaphylaxis management and severity labeling is still a subject of
debate in 2024, even within a specialized allergy department. The lack
of a unanimous international consensus and the multiplicity of published
classifications complicate the management of patients in an emergency
setting. To our knowledge, this study is the first one comparing
different classifications of anaphylaxis and severity levels by using
the WHO classification proposed for the ICD-117 as the
reference one. The results of this study demonstrate a certain degree of
variability in anaphylaxis classification systems and therefore their
implications for treatment management.
Given the multiple definitions of anaphylaxis, several groups proposed
severity scores, often based on expert opinions, but only few of them
have been validated14-17. In our study, each one of
the 4 assessed classification provided different degrees of severity,
when compared with the ICD-11 one. It is clear that the grading value
differ, depending on the evaluated classification: indeed, Muraro’s
classification10 has 3 levels of severity, Blazowski’s
one11 has 4, while those from CoFAR8and Sampson9 go from 1 to 5. Therefore, in clinical
practice, when a patient presents, for example, a reaction classified as
a grade 2 anaphylaxis, this could have a different meaning, following
the used classification, including different possible symptoms and
organs involved, and thus a different therapeutical approach. In his
paper, Blazowski already highlighted the discrepancy between several
classifications, some of them not necessarily used to classify
food-induced anaphylaxis, and he underlined that a new severity grading
system was needed, especially to harmonize the definition of severity
and to avoid any delay in the administration of
adrenaline11. Our work underlines the importance of
using the same classification in a work unit and of communicating which
one is employed, to better approach patients. Also, it would be helpful
to internationally use the same grading system, to better inform and
exchange clear information on patients between physicians. We decided to
refer to the ICD-11 classification as a gold standard since it’s the one
used on a daily base in our unit, and it’s easy to use; it is also the
classification used by the WHO post-coding system, which is already used
and will be even more implemented over the coming years, being available
in all countries for all healthcare professionals and will therefore
allow to identify even cases coded by non-allergists, especially primary
care physicians.
Our study is based on oral food challenge results, during which vomiting
is a common symptom, often combined with other symptomatic elements
warranting the injection of adrenaline18. The most
frequently reported symptom during OFC in our anaphylactic patients was
abdominal pain. This result is noteworthy because abdominal pain is not
always considered as one of the main symptoms of anaphylaxis. Also, in
some countries as in the UK and Australia19, abdominal
symptoms are not considered in the classification of food allergy
reactions. However, the results of our study show that abdominal pain is
often the first symptom found in patients further developing
anaphylactic reactions. Therefore, the question arises as to whether
this reported symptom should be considered as a red flag for a possible
anaphylactic reaction. In our gold standard classification (ICD-11), it
accounts for one organ involvement (the gastro-intestinal track). 98
patients (41.7%) developed anaphylaxis during the oral provocation
test, while none of them had a clinical history of severe reaction. Main
foods associated with a worsening of the reaction, compared with the one
reported in patients’ clinical history, were peanuts (28.8% of
patients), eggs (12.0%), and pistachios (8.0%). On the other hand,
considering patients with a history of anaphylaxis, 45 (19.5%)
presented an anaphylactic reaction during the OFC, while 16 (7%) did
not. These data underline the fact that the evolution of a food allergy
remains often unpredictable, and OFC should be performed only by well
trained professionals, in a safe hospital environment.
Regarding the management of patients, our study revealed a delay, or
even an absence, in the use of adrenaline in cases of anaphylaxis,
regardless of the classification used by the physician. A study by Eller
et al.20 emphasizes the existence of different
severity grading systems for anaphylaxis and the use of adrenaline,
leading to variations in its administration, if based on the grading
system. There are no universally validated diagnostic tools to determine
which symptoms warrant adrenaline treatment compared to those that do
not21, which may explain the underuse of adrenaline
found in our study. A recent study highlights the underuse of adrenaline
even in pediatric emergency services in France22. Such
issue poses a problem in many healthcare institutions, even within a
specialized allergy service, which may be explained by two major
factors: a lack of training in anaphylaxis management and hesitancy
among healthcare professionals to use adrenaline (due to a fear
regarding the bathmotropic effects of adrenaline) as well as simply a
lack of recognition of anaphylactic reactions23.
Additionally, the multitude of existing classifications and their
perceived complexity may also contribute to a less clear indication for
such a vital treatment. What physicians should remember is that
adrenaline is the key treatment of severe allergic reaction, and that
its injection during a positive OFC is safe, even when not strictly
needed24. At the same time, most adverse reactions to
the intramuscular injection are not serious and are transient, while the
risk for a patient experiencing anaphylaxis may raise up to a possible
fatality. These factors show that the risk-benefit ratio is strongly in
favor of the use of adrenaline to promptly treat any anaphylactic
reaction. At last, as for treatment of the reaction, we recorded a
statistical difference in the use of corticosteroids, during an
anaphylactic reaction. Even though such a therapeutical approach is not
recommended5, we could speculate that the fear of not
providing enough treatments wrongly pushed the physicians in including
glucocorticoids in the list of the administered ones.
Our study presents some limitations: it is a retrospective study, and
some data may therefore be missing from the medical records of certain
patients. Also, the choice to use the ICD-11 classification as the
reference one, well-justified for its ease of use in daily practice and
its validation by the WHO as stated above, could potentially introduce
biases. Nevertheless, we also present results that show a certain
strength, considering the number of included patients, the double-blind
verification of the classifications by two specialized allergists, and
the use of four recent classifications for comparison purposes.
While the emergency of different classifications of anaphylaxis and of
its severity is a real asset for clinical management, their multiplicity
create confusion among healthcare professionals. Therefore, it would be
important to consider consolidating these different classifications into
one that is both appropriate and intuitive, favoring sensitivity with a
good compromise regarding specificity. Our work highlights the need to
refine theses scoring systems, to accurately capture anaphylactic
reactions and ensure appropriate management, without neither over- nor
under-treat patients. In conclusion, there is a real need to adopt a
universal, intuitive, and easy-to-use classification, such as the ICD-11
one, while destigmatizing at the same time the use of adrenaline.