- What is Latex Allergy?
- Risk Factors
- Clinical Examination
- How is it Diagnosed
What is Latex Allergy?Latex allergy has become an important health concern in recent years, especially in the occupational setting for health care workers, such as nurses, doctors and allied health professionals. Latex barrier products are now in widespread use following the adoption of universal precautions for infection control, which has been associated with an increased number of people suffering from latex allergy. Latex allergy cannot be cured, however awareness of the problem and avoidance of latex for sensitised individuals remains the mainstay of treatment.
Natural rubber latex is derived from the sap of Hevea brasiliensis. It is the main constituent of over 40,000 medical and consumer products and is used in a wide variety of settings 7. Lists 1-3 detail some of the products that commonly contain latex.
List 1: Uses of natural rubber latex
Latex concentrate (more likely to cause allergic reactions)
- Gloves (40%)
- Adhesives (16%)
- Thread (12%)
- Foam (12%)
- Carpets (7%)
- Imitation leather (7%)
- Other (6%) (includes condoms, medical products, babies teats and dummies)Bulk (dry) natural rubber (less likely to cause allergic reactions)
- Tyres (70%)
- Latex goods (12%)
- Shoes (5%)
- Engineering (3%)
- Cables and tubes (2.5%)
- Vehicles (1.5%)
- Other (6%)List 2: Common medical devices that may contain latex
Note that some of these products are now available in latex free alternatives.
- Bite blocks
- Blood pressure cuffs
- Bulb syringes
- Dental coffer dams*
- Elastic bandages
- Electrode pads
- Endotracheal tubes and airways
- Enema syringes*
- Ventriculo-peritoneal shunts
- Finger cots
- IV access injection ports
- Manual resuscitators
- Penrose surgical drains
- Pulse oximeters
- Stethoscope tubing
- Stretcher mattresses
- Vascular stockings
* Reported as a cause of latex allergy
List 3: Common househould items that may contain latex
Note that some of these products are now available in latex free alternatives
- Carpet backing
- Contraceptive diaphragms
- Elasticated fabrics*
- Feeding nipples
- Household gloves*
- Disposable nappies and incontinence pads
- Infant dummies (pacifiers) and teats for formula feeding
- Rubber bands
- Hot water bottles
- Carpet backing
- Sports equipment
* Reported as a cause of latex allergyIn contrast to natural rubber latex, synthetic rubber latex is produced from petrochemicals and does not contain allergenic latex proteins. Products containing synthetic rubber latex (such as most latex paints, nitrile or neoprene gloves) do not cause allergic reactions.Reactions to natural rubber latex can manifest in 3 different forms. The most severe and important form is an immediate Type-1 hypersensitivity reaction, which is covered here.
Other reactions to latex include:
- atopic dermatitis
“>Allergic Contact Dermatitis, which is a type-4 hypersensitivity reaction which results in eczematous lesions often associated with vesicle formation, after which the skin can become dry, crusted and thickened. Chemical additives such as accelerators and antioxidants are commonly implicated. A change to gloves which do not contain the implicated chemical, or use of cotton lining gloves for protection usually reduces the problem.
- Irritant dermatitis is a non-allergic skin rash characterised by redness, dryness, scaling, vesicle formation and cracking. These changes are caused by sweating or irritation of the glove with the powder residue, or from irritation from frequent washing, soaps and detergents.
Less than 1% of the general population is allergic to latex, however certain people are at increased risk of developing latex allergy, including children with neural tube defects (such as spina bifida) or other congenital abnormalities requiring repeated surgery or catheterisation, and health care professionals who are exposed to latex in the workplace. The incidence of latex allergy is increasing along with the increasing frequency of allergies across the board.
Most people with latex allergy have had frequent exposure to latex over a number of years. Most of these people are nurses, doctors, dentists or other health professionals who are exposed to latex in the workplace, or patients who have had multiple operations or other medical interventions (such as urinary catheterisations or diagnostic procedures), including children with spina bifida or other congenital defects such as renal abnormalities. People who are already allergic to other substances (for example, grass pollen or dust mite) are more likely to become allergic to latex.
Most people with latex allergy have been exposed to latex over several years. With the exception of gloves and balloons, most latex products in daily life do not contain enough allergen to cause significant problems.
Almost half of people with a latex allergy will also develop an allergy to certain fruits, most commonly avocado, banana or kiwi fruit. They will often get itching and/or swelling in the mouth and throat after eating these fruits.
How is it Diagnosed
Diagnosis of latex allergy is largely made on clinical history. Some important aspects of the history include:
- Timing and duration of exposure to latex
- Relationship of latex exposure to onset of symptoms
- Types of symptoms including any suggestion of a generalised or systemic reaction
- Progression of symptoms over time
- Oral reactions to cross-reacting fruits such as banana, avocado, potato, tomato, chestnut and kiwi fruit
- Background history of atopic disorders such as asthma, eczema or allergic rhinitisAllergy invesigations that are available include radioimmunosorbent testing (RAST), skin-prick testing and provocation tests, where exposure to latex is deliberate (such as wearing latex gloves). However, these investigations are usually not useful or necessary. The accuracy of both RAST and skin-prick testing is still controversial, and serious reactions have occurred with both skin-prick and provocation testing for latex allergy. Therefore the diagnosis of latex allergy is usually made on a good history.
Latex allergy can get worse with increasing exposure to latex in some people, thus it is very important to try to limit exposure to latex in people who are allergic. However, many people will only ever experience mild reactions to latex.
There is currently no curative treatment for latex allergy and desensitisation is still in the research phase, however it is showing promise. Therefore, avoidance of latex products is currently the best means of preventing serious reactions in patients allergic to latex.
In patients with a severe latex allergy, these measures should include:
- Provision of a Medic-Alert bracelet
- Use of latex-free gloves (particularly in the workplace)
- Specific measures to create a latex-free or minimised environment in health care settings where latex allergic patients will be treated
- Avoidance of areas where powdered latex gloves are used, as inhalational exposure to latex can lead to life-threatening reactions, and use of powdered gloves increases this risk.
- Preparation for inadvertent exposure to latex, including carrying antihistamines, corticosteroids and adrenaline (EpiPen) as appropriate)
- Carry a supply of latex free gloves for emergencies or procedures with a doctor or dentist
- Education to recognise allergic reactions to latex and what to do in the event of an allergic reaction
- Information about fruits that may cross-react to latex
- Education about products containing latex, including medical products and household products such as gloves, condoms, teats on bottles and dummies,
- Advise all health personnel including doctors and dentists of the allergy
- Avoid food prepared by personnel wearing latex gloves
- ASCIA Education Resources. Patient information bulletin: latex allergy. Australasian Society for Clinical Immunology and Allergy. 2004. Available at: http://www.allergy.org.au/aer/infobulletins/latex_allergy.htm
- ASCIA Education Resources. Professional information bulletin: latex allergy. Australasian Society for Clinical Immunology and Allergy. 2004. Available at: http://www.allergy.org.au/aer/infobulletins/latex_allergy2.htm
- ASCIA Position Paper. Latex Allergy. Australasian Society for Clinical Immunology and Allergy. 1998. Available at: http://www.allergy.org.au/pospapers/latex01.htm
- Cullinan, P. Brown, R. Fieldz, A. et al. Latex allergy: A position paper of the British Society of Allergy and Clinical Immunology. Clin Exp Allergy 2003; 33:1484-99
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- Taylor, J. Erkek, E. Latex allergy: diagnosis and management. Dermatologic Therapy. 2004; 17:289-301