A. Serum tryptase – Explanation
| Anaphylaxis – serum tryptase levels rise following an acute episode |
Serum tryptase levels may remain elevated for up to 12 hours following an acute episode of
anaphylaxis.
Anaphylaxis
Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic
hypersensitivity reaction.
Anaphylaxis is one of the few times when you would not have time to look up the dose of a
medication. The Resuscitation Council guidelines on anaphylaxis have recently been updated.
Adrenaline is by far the most important drug in anaphylaxis and should be given as soon as
possible.
The recommended doses for adrenaline, hydrocortisone and chlorphenamine are as follows:
| Adrenaline | Hydrocortisone | Chlorphenamine | |
| < 6 months | 150 mcg (0.15ml 1 in 1,000) | 25 mg | 250 mcg/kg |
| 6 months – 6 years | 150 mcg (0.15ml 1 in 1,000) | 50 mg | 2.5 mg |
| 6-12 years | 300 mcg (0.3ml 1 in 1,000) | 100 mg | 5 mg |
| Adult and child > 12 years | 500 mcg (0.5ml 1 in 1,000) | 200 mg | 10 mg |
Adrenaline can be repeated every 5 minutes if necessary. The best site for IM injection is the
anterolateral aspect of the middle third of the thigh.
Common identified causes of anaphylaxis
- food (e.g. Nuts) – the most common cause in children
- drugs
- venom (e.g. Wasp sting)
