• 
• 

Three Part Question

[In patients with documented egg anaphylaxis], is [the use of propofol as a sedative/anaesthetic agent] likely to result in an [allergic/anaphylactic reaction]?

Clinical Scenario

As you prepare one of your patients for conscious sedation in the emergency department she tells you that she has been allergic to eggs since childhood. Your colleague states that a documented egg allergy is a contraindication for the use of propofol but you have your doubts. You wonder if there is any published evidence or whether this is another medical myth.

Search Strategy

Ovid MEDLINE(R) 1946–October week 3 2012: (propofol.mp) OR (exp propofol/)] AND [(allergy.mp) OR (exp hypersensitivity/) OR (allerg$.mp) OR (exp anaphylaxis/) OR (anaphylaxis.mp) OR (anaphyl$.mp) OR (egg allergy.mp). OR (exp egg hypersensitivity/)]. Limit to English language and humans only.

Embase 1980–2012 week 42: [exp propofol/] AND [(exp egg allergy/) OR (exp food allergy/) OR (exp allergy/) OR (exp anaphylaxis/) OR (exp allergic reaction/)]. Limit to English language and humans only.

Cochrane Library Issue 10 of 12, October 2012: MeSH descriptor: (Egg Hypersensitivity) explode all trees.

Search Outcome

Ninety-two papers were found in Medline using the stated search strategy, of which two were relevant. Ninety-five papers were found in Embase and 17 in the Cochrane Library.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Hofer et al, 2003, USA	Single Infant	Case report	Anaphylaxis		Case report that implies that the observed anaphylactic reaction was attributable to a pre-existing allergies
Murphy et al, 2011, Australia	28 Egg allergic children (aged 1–15 years) with 43 propofol administrations identified through an 11-year retrospective review. Two children had had egg anaphylaxis, the rest had a positive skin prick test to egg white	Case series	Anaphylaxis	0	Retrospective study
			Allergic reaction	One—in a child with previous egg anaphylaxis

Comment(s)

The main triggers for egg anaphylaxis are the ovoalbumin, ovomucoid and conalbumin proteins contained in the egg white. Propofol contains a purified egg phosphatide but is not thought to be problematical for patients who are allergic to eggs. Reactions to propofol have been shown to be triggered by the iso-propyl or phenol groups rather than the lipid vehicle itself (De Leon-Casasola et al, Laxenaire et al).

Clinical Bottom Line

The use of propofol in patients with simple egg allergy is likely to be safe. A previous egg anaphylaxis is traditionally taught to be a contraindication. The final decision remains at the discretion of the physician after a cautious risk–benefit assessment.

References

1. Hofer KN. McCarthy MW. Buck ML et al. Possible anaphylaxis after propofol in a child with food allergy. Annals of Pharmacotherapy. 2003;37(3):398-401.
2. Murphy A, Campbell DE, Baines D, et al. Allergic reactions to propofol in egg allergic children. Anesth Analges 2011;113:140–4.
3. De Leon-Casasola OA, Weiss A, Lema MJ. Anaphylaxis due to propofol. Anesthesiology Anesthesiology 1992;77:384–6.
4. Laxenaire MC, Mata-Bermejo E, Moneret-Vautrin DA, et al. Life threatening anaphylactoid reactions to propofol (Diprivan). Anesthesiology 1992;77:275–80.