Initial treatment

• Anaphylactic reaction? Airway, Breathing, Circulation, Disability, Exposure

• Diagnosis: look for: acute onset, life-threatening Airway (swelling, hoarseness, stridor) and/or Breathing (rapid breathing, wheeze, fatigue, cyanosis, Sp02 <92%, confusion) and/or Circulation (pale, clammy, low BP, faintness, drowsy/coma) problems, and usually skin changes

• Call for help, lie patient flat, raise patient's legs (if breathing not impaired)

• Intramuscular Adrenaline (1:1000), repeat after 5 mins if no better: adult or child >12 (500 micrograms/0.5mL), child 6-12 (300 micrograms/0.3mL), child <6 years (150 micrograms/0.15mL)

• When skills and equipment available: establish airway, high-flow O2, IV fluid challenge, chlorphenamine, hydrocortisone. Monitor O2 sats, ECG, BP

Confirmation of anaphylaxis

Tryptase is released after anaphylaxis and the rise can be measured within a few minutes, with high levels persisting for more than six hours. Measurement of tryptase can confirm anaphylaxis, reducing the need to look for other causes of the symptoms. Tryptase testing is not usually available in primary care but can be done in the emergency secondary care setting.

Notes from RCGP

• Lack of hypotension, timing and absence of rash mitigate against anaphylaxis

• NSAIDs are a recognised trigger for asthma

• Anxiety does not produce wheezing

• C1 esterase inhibitor deficiency causes angio-oedema

• Scombroid poisoning is caused by bacterial overgrowth in improperly stored dark meat fish (e.g. tuna) and is treated with antihistamines

Follow up

All patients with a suspected or proven anaphylactic reaction should be offered the opportunity to be reviewed in an allergy clinic for further guidance on:

• Confirmation of the diagnosis

• Investigation of possible causes of the anaphylactic reaction

• Advice on future prevention strategies including advice on emergency management

• Education for the patient

Allergy clinics will have differing expertise and competences. It is important to have specialist level referral in cases of severe reactions, diagnostic difficulty, suspected drug-induced, venom anaphylaxis, recurrent anaphylaxis and when several foods are implicated.