Background: Anaphylaxis is increasing at pediatric age; however, its
characterization is hampered by underdiagnosis and underreporting. The
aim of this study was to identify the causes of anaphylaxis in children
and adolescents in Portugal, thus contributing to a better knowledge of
its etiology, clinical manifestations and management. Methods: During a
10-year period a nationwide notification system for anaphylaxis was
implemented, with voluntary reporting by allergists. Data on 533
patients under 18 years of age with anaphylaxis were included. Results:
Mean age was 8.5±4.9 years, 61% were male; 45% had asthma. Mean age at
the first anaphylaxis episode was 5.3±4.7 years (ranging from 1 month to
17 years of age), 63% at preschool age. Most reactions occurred at home
(57%). Food-induced anaphylaxis was the leading cause (77%). The main
culprit foods were cow’s milk (32%), tree nuts (16%), shellfish
(13%), egg (12%), fresh fruits (11%), fish (8%) and peanut (8%).
Other causes included drugs (11%), insect-sting (5%), cold-induced
anaphylaxis (4%), exercise-induced (2%), latex (1%) and idiopathic
anaphylaxis (1%). Most patients (83%) were admitted to the emergency
department; only 46% received adrenaline treatment. Recurrence of
anaphylaxis occurred in 41% of the patients (3 or more episodes in
21%). An adrenaline autoinjector was used in 9% of the patients.
Conclusions: In the Portuguese pediatric population, food is the leading
cause of anaphylaxis. Undertreatment with adrenaline and high recurrence
of anaphylaxis highlight the need to improve both the diagnosis and the
therapeutic management of this life-threatening entity.