Symptoms, severity and timing of reaction
Respiratory (92% vs 90%) and skin (91% vs 94%; p=0.009) were the
organ systems most frequently affected in both subgroups.
Gastro-intestinal symptoms were more common in peanut anaphylaxis (59%
vs 50%; p=0.003) and there was no statistically significant difference
for cardio-vascular involvement between subgroups (36% vs 35%).
According to the Ring&Messmer classification the majority of cases in
both subgroups were labelled as severe anaphylaxis, however
significantly more in the peanut cohort: grade III (65% vs 56%;
p=0.001) and grade IV (1.1% vs 0.9%) (Table 1).
Death was recorded in 0.7% (n=3) in the peanut cohort, and in 0.3%
(n=5) in the other food cohort. The 3 cases of fatal peanut anaphylaxis
occurred in 2006, 2012 and 2013. They were all female teenagers, two of
them had other food allergies/atopic disease, and stress was given as
possible cofactor in one case. First line treatment was unknown in one
case and provided by an emergency professional in the other two, but
only one received adrenaline (i.m. and i.v.) as well as oxygen and i.v.
fluid volume. Other confirmed food triggers causing fatal anaphylaxis
were cow’s milk (2 cases), snail, and poppy seeds, whereas kiwi or
hazelnut were suspected in another case.
Analysis of the interval between exposure and onset of symptoms revealed
no differences between peanut and other food triggered anaphylaxis: 49%
(n=226; specified for 366 out of 459 cases) and 48% (n=714; specified
for 1219 out of 1503) respectively reacted within 10 minutes after
exposure to the trigger, and another 18% (n=83) and 21% respectively
(n=310) within 30 minutes. In both subgroups 6% of the patients
reported a delayed reaction with an
interval of more than 1 hour.
The frequency of biphasic reactions was significantly higher for peanut
anaphylaxis compared to other food triggers (10%, specified for n=404
out of 459, vs 4%, specified for n=1314 out of 1503; p=0.001) (Table
1). The second reaction occurred after more than 12 hours in 21% of the
cases in both subgroups. For peanut anaphylaxis, there were no
statistically significant differences between the biphasic and
non-biphasic reactions in terms of age, reaction severity, and
administration of adrenaline.