Anaphylaxis
Key Messages
Anaphylaxis is an acute severe systemic reaction which is most often allergic (but
can be non-allergic, previously called anaphylactoid). It is commonly associated with
urticaria and angioedema and occurs within minutes (typically less than 1 hour) of a
trigger (eg food/drug/sting). Anaphylaxis is characterised by one or more of:
i)
ii)
iii)
iv)
Airway – tongue/throat swelling, difficulty talking/hoarse voice
Breathing – shortness of breath, wheeze, persistent cough
Circulation – persistent dizziness or collapse, loss of consciousness
Neurological – sense of impending doom, visual changes
NICE guidance is that patients with a history of anaphylaxis should be referred to a
specialist allergy clinic, and according to the specialist services national definition set
17 for allergy, “patients with anaphylaxis must be seen in a specialist allergy centre
and not managed in the community”.
For guidelines describing the management of urticaria and angioedema in the
absence of systemic features see guidance for spontaneous urticaria and
angioedema.
Assessment and Management
1. Anaphylaxis should be treated immediately according to Resuscitation
Council guidelines. Acute measurement of mast cell tryptase (immediately
and 2 hours after the onset of symptoms) should be performed.
2. Identify any potential triggers (eg foods, drugs, stings, exercise) in the 4 hours
before the reaction.
3. 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.
4. Prescribe self-injectable adrenaline (0.3mg x 2) with appropriate training to
patients with:
a. Anaphylaxis (see definition above) or a less severe allergic reaction in
patients with asthma;
And
b. A potentially unavoidable suspected cause.
All patients must have appropriate training in use of self-injectable adrenaline.
Guidance is available at https://www.epipen.com/en/about-epipen/how-to-use-epipen
Version: 3
Date last edited: 10/06/15
Locality; Devon wide
Amendments by: Kevin Bishop
Drug reactions are not an indication for self-injectable adrenaline, as drugs can
usually be avoided unless there is altered consciousness.
Investigations
-
Stings – check specific IgE to bee and wasp venom and mast cell tryptase.
-
Foods – check specific IgE to specific suspect foods 4 weeks after index
reaction. There is no need to investigate foods which have been tolerated
since the reaction as these are not the trigger.
-
Drugs – Ensure potential drug allergies are explained to the patient, and
documented in the medical records with appropriate details.
a. If there is a clear history consider identification jewellery.
Referral
Referral criteria
Include details of index reaction with copy of appropriate correspondence (eg ED
discharge summary) and suspected triggers.
1. Refer all patients with a history of anaphylaxis
a. Patients with drug reactions should be referred if
i. There is diagnostic uncertainty or multiple drugs were involved
(especially where the reaction is systemic)
ii. The suspected drug is essential for the patient’s ongoing
management, and where alternatives clinically not suitable.
Please document reasons for needing treatment with the drug.
2. Patients with a single obvious trigger for their anaphylaxis and no cofactors
(eg asthma, cardiovascular disease) need not be referred routinely.
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Referral Instructions
Refer to Peninsula Immunology and Allergy Service
Refer via DRSS for NEW Devon CCG patients
Choose and Book Selection
Specialty: Allergy
Clinic type: Allergy
Service: DRSS- Western –Allergy & Immunology - CCG - 99p
Referral forms
DRSS Referral form
Version: 3
Date last edited: 10/06/15
Locality; Devon wide
Amendments by: Kevin Bishop
Supporting Information
http://webarchive.nationalarchives.gov.uk/+/www.dh.gov.uk/en/Managingyourorganis
ation/Commissioning/Commissioningspecialisedservices/Specialisedservicesdefinitio
n/DH_4001689
http://www.siaip.it/upload/WAO_anaphylaxis_guidelines.pdf
http://www.resus.org.uk/pages/reaction.pdf
http://www.nice.org.uk/guidance/CG134
Patient information
http://www.nhs.uk/conditions/Anaphylaxis/Pages/Introduction.aspx
http://www.anaphylaxis.org.uk/
https://www.allergyuk.org/severe-allergy-and-anaphylaxis/severe-allergy-andanaphylaxis
http://www.medicalert.org.uk/
Evidence
Pathway Group
This guideline has been signed off by the Western Locality on behalf of NEW Devon
CCG.
Publication date: June 2015
Review date: May 2017
Version: 3
Date last edited: 10/06/15
Locality; Devon wide
Amendments by: Kevin Bishop