Food Allergy


When to consider referral


Referral Criteria

1.    All patients with anaphylaxis unless there is a simple trigger and no cofactors (eg asthma, cardiovascular disease).


2.    Patients with suspected food reactions where food trigger is not clear (eg negative specific IgE testing to the suspected food).


3.    Where multiple foods are implicated.


4.    Where avoidance would cause important dietary restriction (eg nuts in a vegetarian or coeliac disease patient).


5.    Where the allergy has occupational implications (eg military employment).


Type 1 hypersensitivity reactions to food are usually (but not always) associated with one or more of urticaria, angioedema, or local oral symptoms, and occur within minutes (typically less than 1 hour) of ingestion. If there are associated systemic features refer to anaphylaxis guidance.


The symptoms of non-type 1 hypersensitivity (food intolerance) are often gastrointestinal only, and the timing is often not suggestive of type 1 hypersensitivity. 


Eczema alone is not caused by food allergy in adults and this should not be a focus of investigation.



Primary care management prior to referral



1.    Anaphylaxis should be treated immediately according to Resuscitation Council guidelines.



2.    Advise patients to avoid potential triggers identified in the history pending further investigations. If a suspected trigger has been tolerated since the reaction it is excluded as a cause. Advise particular caution when eating away from home or with food not prepared by the patient.


3.    If a food is clearly implicated request specific IgE to the particular food.

a.    There is no role for measurement of total IgE, and do not request testing against foods which were not involved, or which have been tolerated since the reaction.

b.    Negative specific IgE does not completely exclude food allergy or intolerance.  If there is strong clinical suspicion referral to a specialist allergy clinic should be considered.


4.    All patients should be provided with an emergency plan.

a.    Self-injectable adrenaline should be prescribed

                                          i.    Where there were features of anaphylaxis (airway, breathing, circulation, or neurological),

                                        ii.    For all patients with food allergy and a history of asthma

                                       iii.    For patients where access to emergency services might be delayed (eg living in a rural location, travelling to remote area with limited access to healthcare)

b.    Patients with self-injectable adrenaline must have appropriate training. Guidance is available at:




5.    The use of unorthodox methods of diagnosis (eg naturopathy, food-specific IgG testing, vega testing, kinesiology, pulse testing, hair analysis) or treatment (eg homeopathy, acupuncture, reflexology, chiropractic therapy, or osteopathy) has no evidence and should not be used.


Patch testing, skin prick testing, and oral food challenges should not be undertaken in primary care.


Information required with referral


1.    A detailed clinical history and any documentation of reactions.

a.    Foods and medications consumed within 4 hours prior to the reaction

b.    Activities/exercise/exposures over that period

c.    Tolerance of these foods/drugs since the episode (this excludes these as a cause of the reaction).

d.    Any dietary implications (eg nut allergy in a vegetarian or coeliac disease patient).

e.    Any other foods that are avoided and the reason for avoidance


2.    Any specific IgE testing or other investigations that have been done should be included in the referral.


Clinic options available


We have no Choose and Book slots available – we review and triage all referrals ourselves and allocate clinics appropriately.


Review Date                      13/8/2019

Next Review Date           13/8/2020

Author                                  Dr Andrew Whyte, Consultant Allergist and Immunologist, Derriford Hospital

GP Sifter                              Dr Isabel Boyd



Version No.        1.1