Latex allergies

Health and safety fears about latex allergy have prompted some NHS trusts and health boards to consider switching from surgical and examination gloves made of natural rubber latex (NRL) to synthetic alternatives. This strategy may be misguided.


The 2002 Court of Appeal support for a civil claim for damages by a nurse who had developed an allergy as a result of wearing NRL gloves (Dugmore vs Swansea NHS Trust1) was incorrectly interpreted by some to mean that the use of NRL gloves should be outlawed.


Many NHS trusts still believe that the Health and Safety Executive (HSE) has banned NRL gloves. This is not the case, and some trusts may have over-reacted in deciding to switch to a latex-free policy.


Allergy variants


Type I latex allergy is an IgE hypersensitivity to latex proteins in individuals with latex-specific IgE (Immunoglobulin E) antibodies from previous exposure and sensitisation. Type I latex allergy should be distinguished from rubber contact dermatitis, a type IV hypersensitivity to chemicals added to rubber products during their manufacture, which is more common.


NHS trusts are failing to appreciate the difference between type I and type IV latex allergies, and many may not recognise the difference between powdered and non-powdered, low-protein NRL gloves.


Current advice is clear. Guidance for healthcare professionals which accompanies a scientific review of the available evidence2, says that: “By far the most important occupational risk factor for latex sensitisation is the use of powdered latex gloves. Powdered gloves have higher latex allergen content than powder-free gloves, and there is good evidence that their use is associated with a substantially higher prevalence of latex sensitisation.”


NRL is subject to the Control of Substances Hazardous to Health regulations, which state that if exposure to NRL cannot be reasonably prevented, it should be adequately controlled.3


Misconceptions


Healthcare professionals may also mistakenly believe latex allergy is widespread. In fact, the reported occupational prevalence in the UK is probably less than 1 in 200.4-6 The most recent review in 2004 said that sensitisation rates among healthcare workers varied as much as 30-fold – with a far lower proportion having a symptomatic allergy. It adds that the true prevalence of latex allergy among UK healthcare workers remains unclear, “but is probably rare”.7


Following the Dugmore case in 2002, many trusts moved from latex to synthetic nitrile examination gloves. However, guidance was issued to Scottish health boards acknowledging that for surgical procedures, NRL might still be the most appropriate glove.


In 2003, the HSE reported8 that with “prolonged and close skin contact”, NRL gloves were associated with a risk of skin sensitisation. “However, the risk is reduced in gloves with lower levels of latex proteins and process chemicals.”


The HSE concedes that “employers may assess that there is still an operational need for NRL gloves due to their superior microbiological barrier protection, sensitivity and elasticity over other glove materials”.8


It also advises that where NRL gloves are deemed absolutely necessary, single-use NRL gloves with as low a level of extractable (or leachable) protein as reasonably practicable which are also powder-free should be used. Following the Dugmore case, the HSE emphasised that the use of NRL gloves was not illegal, and advised that the risk of allergic reaction caused by natural rubber gloves should be balanced against risks associated with the use of gloves manufactured from alternative materials.8


Material of choice


Meanwhile, the Scientific Committee on Medicinal Products and Medical Devices says that, at present, there does not appear to be any alternative material that can match the safety characteristics of NRL with respect to the transmission of pathogens.9


Furthermore, current Evidence-Based Practice in Infection Control (epic2) guidelines state that NRL remains the material of choice due to its efficacy in protecting against blood-borne viruses and enabling dexterity for the wearer.10


More recently, a UK review of the scientific evidence on occupational aspects of the management of latex allergy has been published jointly by NHS Plus, the Royal College of Physicians and the Faculty of Occupational Medicine.2 This review establishes that:


The use of powder-free, low-protein latex gloves significantly reduces the incidence of latex allergy and latex-induced asthma, as well as latex-related symptoms.


Nationally, switching to such gloves is a proven, effective method of reducing the incidence of latex allergy.


Powder-free, low-protein latex gloves worn by the colleagues of individuals who are already latex allergic or sensitised are as effective at reducing the severity of symptoms as non-latex gloves.


All but the most severe cases of latex allergy and latex-induced asthma can be managed without the need for redeployment, redundancy, or termination of employment, by careful personal avoidance of latex at work, and minor changes in the workplace.


No reports of new cases of latex allergy arising from non-powdered, low-protein latex gloves were found during this review.


It reiterates: “The evidence does not support, therefore, a complete ban on the use of latex gloves.”


Further guidance for healthcare professionals has been published alongside the NHS Plus review:


Powdered latex gloves should not be used in the workplace when powder-free latex gloves are available.


Alternatives to latex gloves may have other problems, particularly barrier integrity after use, user satisfaction, barrier effectiveness and other possible allergic reactions.


A switch to powder-free latex gloves can be cost-effective.


Despite all this convincing evidence, increasing numbers of NHS trusts are starting to use gloves manufactured from synthetic nitrile, polyisoprene and polychloroprene rather than those manufactured from NRL. This raises a number of concerns:


Synthetic gloves are usually of a lower tensile strength than NRL, and once stretched, do not fully recover.


They usually have poorer grip and sensitivity. This combination of factors may affect tactile sensation and dexterity.


Synthetic gloves may contain high levels of the accelerator linked to type IV sensitisation.


Risks


Accelerators, used in the manufacture of gloves made from both NRL and synthetic materials, can produce delayed type IV hypersensitivity reactions. There may be higher residual levels of accelerator chemicals in synthetic gloves, because they are not subjected to the same high temperature leaching and chlorination processes as NRL gloves.


In 2005, the Medical and Healthcare Products Regulatory Agency issued a medical device alert that some synthetic, latex-free surgical and examination gloves degrade and may disintegrate when in contact with certain solvents (eg acetone, which is present in products such as spray-on wound dressings).11


Meanwhile, surgeons are now being advised to double-glove as a method for reducing needlestick injuries and blood-borne viruses. Double-gloving with synthetic gloves is largely untested, and could have an adverse effect on dexterity and may lead to an increase in the incidence of repetitive strain injuries.


Operating theatre personnel may be under the misconception that if they transfer to synthetic, latex-free gloves it obviates the need for surveillance. It does not. There may still be adverse type IV skin reactions to synthetic or nitrile gloves.


A wholesale change from latex to synthetic gloves may lead to an increase in staff unable to wear gloves at all – with increasing type IV allergy as a result of using nitrile gloves, and increasing unavailability of gloves manufactured from NRL. It should also be recognised that if a glove user develops a type IV hypersensitivity, they will not be able to return to an NRL glove, as the same accelerators are used in both types of gloves.


Some trusts have been served with improvement notices by the HSE, taking this to mean that the HSE is directing them to go latex-free. Again, this is categorically not the case. The HSE is simply trying to ensure that trusts have a valid latex policy in place.


The NHS Plus review is a welcome development. It makes it clear that the evidence does not support a ban on the use of NRL gloves, and that there is – as yet – no valid reason to transfer from latex to non-latex gloves within the healthcare environment.


Main conclusions




  • The selection, purchase and use of gloves should be evidence-based.


  • The NHS Plus review of the scientific evidence provides a powerful argument for trusts not to be bullied into adopting a latex-free strategy.


  • Powder-free, low-protein latex gloves significantly reduce the incidence of latex allergy, as well as the prevalence of latex-related symptoms.


  • It is ill-advised for NHS trusts to withdraw NRL gloves across all areas, including surgery, as a knee-jerk reaction fearing litigation.


  • Policies should ensure that operating theatre staff have the best possible protection from needlestick injuries and blood-borne viruses. Gloves manufactured from NRL are durable and flexible, giving wearers dexterity, sensitivity and microbiological protection. Gloves manufactured from a synthetic material have a lower tensile strength and barrier protection may be compromised.


  • NHS trusts should assess the true incidence of sensitisation and chemical allergy to formulate their latex allergy and glove use policies, adopting a risk assessment process which takes account of the occupational risk and control measures required.


  • Those who change to latex-free gloves who develop a type IV sensitisation will not be able to return to using NRL gloves.

References




  1. Dugmore vs Swansea NHS Trust and another, Court of Appeal (Civil Division [2002] EWCA Civ 1689


  2. NHS Plus, Royal College of Physicians, Faculty of Occupational Medicine. Latex allergy: occupational aspects of management. London, RCP, 2008


  3. Control of Substances Hazardous to Health Regulations 2002, (COSHH) Approved Codes of Practice, HSE Books (COSHH). (updated 16/05/2008 accessed 7/08/2008).


  4. Smedley J, Jury A, Bendall H, Frew A, Coggon A (1999). Prevalence and risk factors for latex allergy: a cross-sectional study in a United Kingdom hospital. Occup Environ Med56(12):833-36


  5. Chowdhury MM, Statham BN (2003). Natural rubber latex allergy in a health-care population in Wales. Br J Dermatol148(4):737-40




  6. Cullinan P (2004). Latex allergy. CPD Bulletin Immunol and Allergy3(3):82-84


  7. Health and Safety Executive, Field Operations Directorate, Service Sector. Natural Rubber Latex sensitisation in healthcare. Sector Information Minute (SIM) 7/2003/24. 2003


  8. Scientific Committee on Medical Products and Medical Devices (SCMPMD). Opinion on the protection offered by natural rubber latex medical devices against transmissible diseases. Technical report: European Commission Health and Consumer Protection Directorate-Genera. October 16, 2003


  9. Pratt RJ, Pellowe CM, Wilson JA et al (2007). epic2: National evidence-based guidelines for preventing healthcare-associated infections in NHS hospitals in England. J Hosp Infect65(suppl 1):S1-S64




  10. Tanner J, Parkinson H (2006). Double-gloving to reduce surgical cross-infection. Cochrane Database of Systematic Reviews. Issue 3 (first published online, July 19, 2006)

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