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This document has been prepared by a Working Party of The Australasian Society of Clinical Immunology and Allergy.
| Convenor |
Connie Katelaris
MBBS PhD FRACP
Senior Consultant
Clinical Immunology and Allergy
Westmead Hospital
Westmead NSW 2145
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| Working Party Members |
Helen Kolawole, FANZCA
Specialist Anaesthetist
Peninsula Health Care network
Department of Anaesthesia
PO Box 52
Frankston VIC 3199
Richard Widmer, MDSC FRACDS
Associate Professor, Paediatric Dentistry
Westmead Hospital
Westmead NSW 2145
Janice Labbett, RN, Grad. Dip. Management
Senior Nurse Manager
Operating Suite
Westmead Hospital
Westmead NSW 2145
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(revised 6/98)
Preamble
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.
Glossary of terms
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.
Introduction
Over the last decade, there has been a marked increase in reports of
the development of latex allergy in certain at-risk groups. This
co-incides 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.
Irritant Dermatitis
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.
Allergic Contact Dermatitis
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 to Latex
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.
Appropriate Handcare Education
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.
Public Health Issues
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. he 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
References:
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.
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