This document has been prepared by a Working Party of The Australasian Society of Clinical Immunology and Allergy (ASCIA).
MBBS PhD FRACP
Clinical Immunology and Allergy
Westmead NSW 2145
|Working Party Members||Helen Kolawole, FANZCA
Peninsula Health Care network
Department of Anaesthesia
PO Box 52
Frankston VIC 3199
Richard Widmer, MDSC FRACDS
Janice Labbett, RN, Grad. Dip. Management
The information contained in this document has been prepared with great care and is accurate at the time of publication. As the constituents of products are constantly changing and products are regularly removed or added to the market, individuals should check the particular product for latex content before use.
Throughout the literature on this topic, a number of terms are used which are sometimes confusing. For the purposes of this document, the following terms are explained.
Type 1 hypersensitivity: an immunologically mediated reaction involving IgE mediated mast cell degranulation resulting in the clinical manifestations of allergic reactions.
Type 4 hypersensitivity: an immunologically mediated reaction involving sensitised T cells which mediate delayed type hypersensitivity reactions resulting in allergic contact dermatitis. Type 1 and Type 4 reactions may occur in the same individual and indeed, the development of contact dermatitis may precede the onset of IgE mediated symptoms. Although not life-threatening as may be Type 1 reactions, Type 4 reactions can be very severe and associated with significant morbidity. Therefore, patients with this sensitivity must be handled in a manner similar to the Type 1 sensitive individual with the exception that they do not require a powder free environment.
Latex: the milky sap of the tree Hevea brasiliensis from which natural rubber is manufactured.
Natural rubber: rubber manufactured from latex.
Synthetic rubber: rubber manufactured from petrochemicals ; does not pose a threat for latex-allergic individuals.
Latex allergy: Type 1 hypersensitivity to certain latex proteins in natural rubber. This is also referred to as Natural Rubber Latex allergy by many authors.
Rubber allergy: a confusing term generally used to refer to delayed type hypersensitivity reactions to the chemicals in natural rubber(eg. accelerants, preservatives) resulting in allergic contact dermatitis.
Over the last decade, there has been a marked increase in reports of the development of latex allergy in certain at-risk groups. This coincides with the great increase in latex glove use following the introduction of universal precautions.
Latex is most often associated with disposable gloves, however, other items which may contain latex include catheters, dressings and bandages, intravenous tubing, syringes, stethoscopes and airways. It is now clear that frequent users of latex products may develop allergies to the latex proteins, with resulting allergic reactions ranging from contact urticaria through to life-threatening anaphylactic reactions.
The manufacturing process to produce latex gloves is complex. After the harvesting of latex from the tree Hevea brasiliensis, ammonia and other preservatives are immediately added to the milky latex to prevent contamination and degradation. During the manufacturing process other chemicals, including antioxidants and accelerators, are added to give the latex its desirable properties. Porcelain moulds are dipped into the latex concentrate to produce products such as gloves, balloons and condoms.
Such chemical additives can be responsible for local skin reactions but these chemicals are not the cause of immediate generalised allergic reactions, which are almost always due to IgE mediated sensitivity to the latex proteins.
There have been reports of problems with latex gloves in the workplace for many decades. The commonest problem is that of an irritant dermatitis. This is a non-allergic skin rash, characterised by erythema, dryness, scaling, vesiculation and cracking. Such changes are caused by sweating or irritation of the glove with its powder residue, or from irritation from frequent washing, soaps and detergents.
Contact dermatitis is a Type 4 mediated immune response where sensitised lymphocytes react to the chemical additives in the gloves. Such delayed hypersensitivity results in an eczematous lesion, usually on the dorsum of the hands, and often associated with vesicle formation. The skin may then become dry, crusted and thickened. Chemical additives such as accelerators and antioxidants (e.g. thiurams and carbamates) are commonly implicated. Diagnosis of this problem is conducted with patch testing. A change to gloves which do not contain the implicated chemical or the use of cotton lining gloves for protection under the gloves usually reduces the problem.
Immediate hypersensitivity reactions caused by latex may result as a consequence of contact with products such as latex gloves, or by inhalation of allergenic latex proteins which become adsorbed to the glove powder. Direct exposure to latex at mucosal surfaces, which occurs following catheterisation and other procedures, may also be a route of sensitisation.
A full range of allergic symptoms, including allergic rhinoconjunctivitis, urticaria and angioedema, asthma, anaphylaxis and death have all been well documented as a result of sensitisation to latex.
Following the emergence of latex allergy, certain populations have been recognised as being at risk for developing latex allergy. Such groups include:
- children with spina bifida and other congenital urogenital abnormalities
- health care workers
- rubber industry workers
- individuals undergoing multiple surgical procedures, particularly if they are atopic
- certain individuals with food allergies.
Recently, two studies have been published indicating the risk of sensitisation in Australian health care workers. Katelaris et al conducted a questionnaire survey of dental workers in a large dental facility in western Sydney. Sixteen of 177 respondents reported characteristics suggestive of latex allergy.
A second study investigated the prevalence of latex allergy among nurses working in an Australian hospital. Five glove extracts were used in skin testing: 22% of 140 nurses were skin test positive to at least one of the skin test reagents. These 2 two studies indicate that latex allergy is likely to become a significant occupational health issue in Australian health care workers.
There are descriptions of patients presenting with latex allergy who do not fit any of the above categories. Therefore, latex allergy has been reported in the absence of known risk factors.
Many studies have shown that health-care professionals with atopic dermatitis and hand eczema appear to have a greater chance of becoming sensitised to latex proteins. Thus, careful attention to hand washing technique and barrier protection is essential to minimise this risk.
From a public health perspective, there is now overwhelming evidence that the impact of latex allergy on latex-allergic health care workers and, indeed, good preventative strategies to minimise further latex sensitisation, can be achieved by the following measures:
1. The introduction of powder free gloves universally throughout medical facilities will immediately minimise sensitisation via the inhaled route.
2. Move to purchasing only low allergen-containing gloves to minimise the risk of sensitisation through compulsory glove wear. This strategy requires the co-operation of industry and the insistence on declaration of allergen content on glove products, to allow the rational purchase of such low-allergen gloves.
3. The identification of high risk individuals in the health care setting so that specific counselling may be undertaken to lessen the individual's risk of sensitisation.
There are many gloves on the market and it is no longer acceptable to buy a glove because it costs less or an individual believes it feels better on their hands. There are Australian standards for both sterile and procedural / examination gloves which address design, properties and labelling (AS 4179-1994, AS 4011-1995). There is a need to evaluate manufacturers' information on latex, non-latex and vinyl gloves in the areas of barrier protection and durability.
Other strategies which are recommended to address the problem of latex sensitisation include:
1. The removal of the term hypo-allergenic when referring to surgical gloves. This term is now most misleading in the present context of immediate hypersensitivity to latex. It was coined to refer to gloves which had a lower chance of producing allergic contact dermatitis via chemical additives. It was never intended to refer to latex protein content. The term should now be discarded.
2. Manufacturers should be strongly encouraged to label surgical glove products according to the chemical additives used and to the latex allergen content.
3. Endeavours to produce more acceptable powder-free gloves should be strongly encouraged. The US FDA has introduced a rule regarding labelling of medical devices and packaging containing natural rubber latex. This will take effect from September 30, 1998. The Australian Therapeutic Goods Moderator (TGA) is currently in the process of reviewing device labelling based on the European Union Directive. These initiatives will allow ready identification of latex containing medical devices. As a result care of patients with latex allergy will become easier.
4.Endeavours to produce effective, latex-free condoms should be strongly encouraged. It is likely that such condoms will be more expensive than their latex counterparts. Strategies should be considered for subsidising such condoms for safe sex practices in those confirmed with latex allergy.
The following guidelines and information sheets have been devised to address the problem of latex allergy in a number of settings:
- hospital wards
- hospital operating suites
- general consulting rooms
- dental general practices
- guidelines for the latex allergic individual
- guidelines for new employees
Australian Standard. Single use (sterile) rubber surgical gloves. AS 4179-1994.
AustralianStandard. Examination and procedural gloves for general medical and dental use. AS 4011-1995.
Edit. Latex allergy - an emerging healthcare problem. Annals of Allergy, Asthma and Immunology 1995; 75: 19-21.
Douglas R, Morton J, Czarny D, O'Hehir RE. Prevalence of IgE-mediated allergy to latex in hospital nursing staff. Aust NZ J Med 1997; 27:165-169.
Katelaris CH, Widmer RP, Lazarus RM. Prevalence of latex allergy in a dental school. Med J Aust 1996; 711-714.
Kelly KJ, Kurup VP, Reijula KE and Fink JN. The diagnosis of natural rubber latex allergy. J. Allergy Clin Immunol 1994; 93: 813-6.
Slater J.E. Latex allergy J Allergy Clin Immunol 1994; 94: 139-49.
Turjanmaa K. Incidence of immediate allergy to latex gloves in hospital personnel. Contact Dermatitis 1987; 17 : 270-5.
Content updated March 2010