Safety
Tree nuts have the potential to trigger severe allergic reactions in
susceptible children and there is a risk of reaction in both the multi
nut and home introduction arms of the TreEAT trial. To date there is a
paucity of data on the type and severity of tree nut reactions in
infancy and on first exposure. However, low risk of severe reactions on
first exposure have been reported to peanut [26] and it has been
suggested that the risk of severe reactions may be age related [17].
Our published data for cashew nut challenges indicate that
<2% of positive cashew nut challenges involve the development
of anaphylaxis [27].
In the home introduction arm, the
risk and severity of potential reactions will be minimised by following
the cautious graded home introduction protocol with dose escalation
daily. All participants will be provided with an ASCIA Allergy Action
Plan [28] outlining the signs and symptoms of an allergic reaction,
and appropriate treatment including the use of antihistamines and
adrenaline auto injectors if required. This information is also included
on the Home introduction of tree nuts TreEAT trial information provided
to families.
It is not known if giving tree nuts
together in a mixed nut butter in the multi nut OFC group may increase
the risk or severity of an allergic reaction. However, the overall dose
of each tree nut protein in the multi-nut butter is lower than that
given in an individual nut OFC (1g versus 2-4g depending on OFC top
dose). The risks are mitigated with specialised allergy trained nursing
and medical staff supervising the OFCs and anaphylaxis rescue medication
(adrenaline) and full resuscitation equipment on standby. Additionally,
the multi-nut OFCs will be done in the Melbourne Children’s Trial Centre
which is co-located at Australia’s largest tertiary paediatric
children’s hospital, Royal Children’s Hospital Melbourne.
There is a risk of discomfort and minor bruising, swelling or bleeding
following a blood test. Finally, there is the inconvenience to the
families of attending clinic and possible additional OFC appointments.
We assess that the study benefits outweigh the potential risks.