Chlorhexidine allergy
We received correspondence about a case in which a patient with known chlorhexidine sensitivity had a chlorhexidine-impregnated central line inserted and suffered a fatal anaphylactic reaction. Readers may have seen the letter in Anaesthesia News [1]. The authors make the point that NAP6 [2] identified chlorhexidine as the third most common trigger of anaphylaxis, being responsible for 10% of cases (0.78 per 100,000). The recommendation in the report of NAP6 said “The MHRA should work with manufacturers of medical devices… to ensure that products are labelled clearly and prominently, to identify whether they contain chlorhexidine or not”. The MHRA released a Medical Device Alert in 2012 on this topic.[3]
The letter authors pointed out that ISO specifies an approved symbol to identify when a product contains latex [Fig 1]. They suggested that it would be sensible to have such a symbol for chlorhexidine, given that it is a more common cause of anaphylaxis than latex.
As a consequence, we have made contact with representatives who sit on the relevant ISO committees and they are going to take this suggestion forward. For those with an interest in the detail, to complete the work would require adding a new symbol in ISO 15223-1 (Medical devices – symbols to be used with information supplied by the manufacturer) and updating ISO 10555-1 (Intravascular catheters - Sterile and single-use catheters) to require its use. Even without this, ISO 7000-2725 (Graphical symbols for use on equipment — Registered symbols) means that manufacturers can already use the triangle symbol to warn of any substance in medical devices, with whatever text they choose, but it would not be standardised. We will highlight this with our industry partners.
As an invasive procedure, central line insertion comes under the auspices of NatSSIPs and consequently organisations should have a LocSSIP to cover it. As an additional safeguard, organisations could include a specific question to check whether or not the line selected contains chlorhexidine.
References
[1] Panesar GS, Hanmer SB. Highlighting inadvertent exposure to chlorhexidine in medical devices. Anaesthesia News, September 2023
[2] Garcez, T. Chlorhexidine. Anaesthesia, Surgery and Life-Threatening Allergic Reactions: Report and Findings of the Royal College of Anaesthetists’ 6th National Audit Project- Perioperative Anaphylaxis Royal College of Anaesthetists, London 2018 [Accessed 4/1/2024]
[3] Medical Device Alert (MDA 2012/075): All medical devices and medicinal products containing chlorhexidine - Risk of anaphylactic reaction due to chlorhexidine allergy. MHRA, 2012 [Accessed 4/1/2024]
Fig. 1 ISO symbol for items containing latex
