Recently a patient died after suffering from an allergic reaction to Chlorhexidine. David Reissner discusses this issue and provides some recommendations.

The recent Coroner's Inquest into the death of a patient after suffering from a fatal reaction to mouthwash given by his dentist1 will give dentists cause for concern, particularly because the February Inquest into the death of Graham Dalby was followed in late March 2011 by reports of the death in a Brighton dentist's chair of Sacha Rumaner2 after a suspected fatal reaction to mouthwash.

In the case of Mr Dalby, an allergy to latex was ruled out by the coroner after hearing at the inquest that before treatment the practice had requested information regarding allergic reactions and Mr Dalby had stated that he had been allergic to rubber but not latex.

Mr Dalby's dentist, Rachael Gibson, had used chlorhexidine, a commonly used antibacterial solution contained in mouthwash, to wash his tooth socket. Unfortunately Mr Dalby suffered from anaphylactic shock inducing a cardiac arrest.

The Oxford Journal reported on 26th March 2009 that chlorhexidine has been widely reported to cause IgE-mediated allergic reactions (from urticaria and angioedema to anaphylaxis) among patients undergoing surgery/invasive procedures. The study concluded after identifying four cases of chlorhexidine allergy among heath care workers that despite its excellent antimicrobial properties, chlorhexidine is an occupational allergen.

Dentist should therefore be aware that the use of mouthwash containing chlorhexidine runs a risk of a patient having an adverse allergic reaction and should therefore take steps to assess the patient's full medical history to identify whether they suffer from allergies.

Staff at the Penrith practice were praised during the inquest by several medical experts in their handling of the incident and believed that Mr Dalby had received the best possible treatment. This included the senior dentist recognising the symptoms of anaphylactic shock whilst Mr Dalby was still at the chair and injecting Mr Dalby with adrenaline, the common method of treatment for such adverse allergic reactions. Two senior dentists and a paramedic treated Mr Dalby at the scene, but his reaction was so sever that he went into respiratory arrest and died at the Cumberland Infirmary on 10th October 2009 without regaining consciousness.

The Coroner returned a verdict of accidental death and the coroner expressed concern that an allergic reaction suffered by Mr Dalby whilst visiting the Cumberland Infirmary in Carlisle in 2002 had not been sufficiently investigated at the time. If it had been it may have given Mr Dalby sufficient information to prevent a further allergic reaction on a subsequent occasion, leading to his death.

John Lewis, the practice owner of the Penrith's Ghyllmount practice, recently expressed his views regarding the incident and how the investigation had been handled. Dr Lewis stated that he would recommend the following to dental practitioners:

  • Pre-register your location with ambulance control using "point taken"
    The Ghyllmount dental practice was a new build and as such was not recognised in the satellite navigation system. Ambulance control had become regionalised and local knowledge had become lost. It had taken 6 minutes for the paramedics to arrive but 30 minutes for the ambulance to arrive. By pre-registering your location you can save vital minutes in an emergency.
  • Update your allergic questionnaire
    Dr Lewis has stated that the BDA medical history questionnaire was inadequate in respect of allergies, his practice has now designed one that includes a more comprehensive guide and his practice regularly uses the Heath and Safety Executive guide on allergic screening. Dentist should therefore take the time to assess whether their measures for medical history and allergies should be updated in light of these events.
  • Become a more allergic free practice
    The Ghyllmount practice has become latex free and now used hypo allergenic products wherever available. This may prevent and minimise risk of adverse allergic reactions.
  • Signed care/treatment plans
    Dr Lewis has stated that computer records alone are not sufficient for the purposes of a police investigation. It is good practice to have signed updated medical history at the start of each treatment and recommended that where treatments include any amendments these should also be signed and placed with the patient file.
  • Next of Kin Form
    Unfortunately it had taken 3 days to find and inform the family of the incident as Mr Dalby had written the wrong telephone number in his medical history form. Dr Lewis's practice now has a 'next of kin' form. However practitioners should be aware that where such forms are used they should be regularly checked to see whether the information continues to be correct and updated where and when necessary.
  • Use of training and knowledge
    Dr Lewis recommends that practitioners do not hesitate to take control and to use their training and knowledge when dealing with emergencies; and also not to assume that the paramedic will be more experienced. The practice and staff were praised at the inquest in the way that they had dealt with the incident including knowledge of anaphylactic shock and taking control of treatment by injecting adrenaline.
  • The vital importance of training
    The practice staff had regular training and was up to date with their training. The practice was praised in observing all proper procedure at the inquest.

Measures such as signed updated medical records and requesting that patients complete a comprehensive allergic reaction forms may cause some patients or even practice staff to complain about over-regulation or inducing overly bureaucratic procedures however having such measures in place may prevent a tragic event such as Mr Dalby's taking place in the first place. It is too soon to comment on the death of Sacha Rumaner and whether it was a reaction to mouthwash, as suspected. An Inquest into her death took place on 15 February 2011.


1. Vol . 59 Issue 4 p270-272

2. Metro, 23 March 2011

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.