Latex Allergy Diagnosis and Management
Updated: January 2022
Originally Posted: July 2004
2016: Sandra M. Gawchik, DO
Asthma & Allergy Associates
West Chester, Pennsylvania, USA
2022: Professor Connie Katelaris, MD, PhD
Clinical Associate Professor, Dept. of Clinical Immunology and Allergy
Westmead Medical Centre
Professor Connie Katelaris, MD, PhD
Clinical Associate Professor, Dept. of Clinical Immunology and Allergy
Westmead Medical Centre
The term “latex allergy” has been applied to a number of clinical conditions. Adverse reactions to latex depend upon the underlying mechanism and route of exposure. Natural rubber latex (NRL-1,4 cis-polyisoprene) comes from the sap of the rubber tree, Hevea brasiliensis grown predominantly in Southeast Asia. It is processed in one of two ways with 90% used to manufacture moulded rubber products such as tyres, shoe soles and a vast array of other products, whereas 10% is ammoniated and used to make dipped rubber products such as latex gloves, condoms and balloons. Low molecular weight additives such as antioxidants and accelerants are usually added in these processes.
The most common condition seen in association with latex glove use is an irritant contact dermatitis caused by a combination of sweating, friction and frequent hand washing. An allergic contact dermatitis, a T-cell mediated delayed type hypersensitivity reaction can occur as a reaction to one of the chemical additives (eg. thiurams, carbamates).
Type 1 hypersensitivity reactions to NRL proteins , the subject of this review, may present with various clinical manifestations.
Allergic contact urticaria
60-80% of health care workers who are allergic to latex report contact urticaria. This is the most common early manifestation of latex allergy. Symptoms of pruritus and typical urticarial lesions develop within 10-15 minutes after gloves are donned and can pre-date more serious reactions.
Rhinitis conjunctivitis and asthma
Rhinitis, conjunctivitis and asthma can occur in latex sensitive individuals on exposure to aerosolized latex protein adherent to cornstarch powder when gloves are donned and removed. Symptoms such as ocular tearing and itching, nasal congestion, itching, sneezing and rhinorrhea may frequently be confused with seasonal pollen allergies. It becomes important to correlate these to latex aeroallergen exposure. Asthma can occur as an isolated exposure to latex in patients not previously diagnosed with asthma.
These individuals will experience chest tightness, wheeze, shortness of breath, dyspnea and/ or cough. They should be removed from the work environment unless exposure can be eliminated.
This most serious type 1 IgE-mediated reaction can occur in both medical and non- medical settings. This life-threatening allergic reaction can occur intraoperatively during surgical, obstetrical, gynecologic, dental and other medical procedures. In addition, exposure to products such as toy balloons, condoms, diaphragms and pacifiers can precipitate an anaphylactic reaction.
RISK FACTORS for development of latex allergy
In the health care community, the main risk factors are occupational exposure and atopy. Individuals allergic to foods such as fruits and vegetables, or with atopic dermatitis, have a higher rate of latex allergy. The presence of hand dermatitis in a healthcare worker is also viewed as a risk factor.
OCCUPATIONS WHERE LATEX GLOVES ARE USED
There are many occupations where workers are exposed to frequent glove use and these are not confined to the healthcare sector. Some examples are:
- Health care professionals - medical, surgical, nursing, dental professionals, ambulance attendants
- Food handlers/restaurant workers
- Domestic workers
- Rubber industry workers
MEDICAL CONDITIONS ASSOCIATED WITH INCREASED LATEX SENSITIZATION
There are certain patient groups that have an increased risk of developing latex allergy. Those patients who have had multiple surgical procedures carry a greater risk as do those who require frequent cateterisation or instrumentation. Some examples a stated below:
- Spina Bifida
- Urogenital abnormalities
- Imperforate anus
- Tracheo-esophageal fistula
- Multiple congenital anomalies
- Ventriculo-peritoneal shunt
- Cerebral palsy
- Pre-term infants
DEVELOPMENT OF LATEX PROTEIN ALLERGY
Latex proteins can sensitize in the following manner:
- Inhalation of latex adherent to powder particles as gloves are donned and removed.
- Absorption through the skin when the barrier integrity is disrupted by trauma, irritation, contact dermatitis or eczema.
- Absorption through mucous membranes when latex protein becomes solubilized by body secretions with condoms, internal exams or intraoperative or dental procedures with latex gloves.
- Direct entry into the body when latex protein is present in intravenous injection ports, surgical equipment
Allergy to natural rubber latex is an important clinical condition that occurred after the institution of universal precautions. There was a rapid rise in the production of latex gloves with the institution of universal precautions to meet the needs of health care workers. This resulted in an epidemic of latex allergy in health care workers in both medical and dental environments as well as individuals with specific health problems such as spina bifida, myelodysplasia, urogenital abnormalities, multiple surgical interventions, and food allergies (bananas, kiwi, avocado, and chestnuts.
Allergies to natural latex gloves were identified as a serious health care problem in the late 1980s and 1990s.. At its peak, up to 17% of health care workers were sensitized to latex with huge losses to the health care workforce. Seventy percent of the spina bifida population had become sensitized and were at risk of severe reactions or death during procedures such as catheterisations. With introduction of powder-free gloves rates fell to 4-7% and have decreased further where latex-safe environments have been established.
In the 1990s, surveys of sensitization to latex allergens in the general population found rates to be between 3-9.5 %. In countries where public health measures to reduce sensitization occurred, this rate fell to below 1% in the general population. Over the past decade, while the incidence has decreased due to the recommendation of avoiding powdered latex gloves, the problem has not disappeared and has continued as a result of inadvertent exposure to latex from less obvious sources, e.g., balloons and hair extensions. It remains high in third world countries where powdered latex gloves continue to be used as they are cheaper than the non-latex alternatives.
HEVEA LATEX ALLERGENS
Approximately 250 different latex polypeptides have been identified of which 60 have been able to bind to human IgE. Only 15 have been well characterized and given a designation by the World Health Organisation/IUIS Allergen Nomenclature Committee. Specific latex allergens are associated with specific clinical situations. Hev b1 and 3, membrane-bound elongation proteins, are associated with latex allergy in spina bifida patients. They require direct mucosal contact as during surgery for sensitization to occur. Hev b 5 acidic protein and Hev b 6.01/6.02 are soluble allergens and are the major allergens involved in sensitizing health care workers. These proteins are released from dipped products, primarily latex gloves that have been coated with powder. Donning and removing gloves aerosolizes the powder to which the latex is adherent. In occupations requiring frequent protective glove use, alleren exposure and sensitisation occurs via direct contact or by inhalation.
A number of latex allergens belong to families of defense proteins and are related to lipid transfer proteins or profilin, having structural homology with certain plant foods. This is the reason why 30%-50% of those allergic to latex have hypersensitivity to some plant foods, especially certain fruits, known as the latex-fruit or latex-food syndrome. Many plant-derived foods have been associated, with the most common being banana, kiwi fruit, avocado, chestnut, papaya, tomato and potato.
Diagnosing latex allergy can be challenging
The most important part of the evaluation is a thorough history and physical examination, noting the temporal relationship of clinical symptoms to exposure to latex. This is supplemented with appropriate tests. This holds true throughout the world. One questionnaire regarding latex allergy, for example, is available from the American Latex Allergy Association and this form is helpful in evaluating patients. In the United States, there are no FDA extracts available for latex skin testing but in vitro testing is available. Thus in the United States, the first step in the evaluation of latex allergy is the clinical history followed by in vitro immunological testing if the history is supportive of an IgE mediated reaction.
Latex skin testing materials are available from commercial sources in Canada, Europe and Australia. When skin test materials are standardized in terms of their allergen content and stability they are a safe and effective diagnostic procedure and skin testing is the testing method of choice when available. Skin prick tests are done first. At times when the skin testing is inconsistent with the history, specific IgE antibody testing may also be needed. Provocation testing is not recommended due to the inherent risk.
In Europe and Canada, the three commercially available glycerinated H.brasilienesis extracts are prepared from Hevea B and C serum proteins from sterile ammoniated or non-ammoniated latex. The non-ammoniated C serum extract is felt to be comprehensive in its allergen composition.
The two serological tests currently available throughout the world are Thermofisher Scientific/Phadia ImmunoCAP and Siemans immunolite assay. Currently, an ImmunoCAP ISAC that contains recombinant Hev1, 3, 5, 6, and 8 is under investigation. The strength in this test is in identifying sensitized but asymptomatic individuals with cross-reactive latex profilin (Hev b 8). In the United States, serological testing is used as the method of choice to confirm the clinical history as skin testing materials are not commercially available.
Patients with a clinical history of latex allergy can have negative results on skin testing and serological testing. This can be due to an inadequate number or quality of testing materials. Therefore, clinical judgment is an important component in the diagnosis.
At the present time, skin tests and /or serologic tests are not indicated for screening the general population given the performance characteristics of the tests.
The principal approach to, and most cost-effective management of, latex allergy is avoidance! Several other therapeutic approaches have been investigated including immunotherapy and the use of anti-IgE antibody treatment but neither have shown much promise.
Rational approaches to avoidance can be considered from the point of view of manufacturing processes, institutional work practices and approaches directed to the latex-allergic individual.
Over the years since the epidemic was recognized, producers of rubber gloves have made significant changes to manufacturing practices. Addition of a chlorination process has resulted in lower NRL allergen content and removal of any powder has dramatically decreased aerosolized particles and environmental contamination with latex allergens. Usage of non-latex gloves has become widespread and their quality has improved over the years.
Creation of “latex safe” environments in institutions where glove usage is frequent, such as medical facilities, has been a major driver for lowering the sensitisation rate and for creation of a safe work environment for those who are sensitized. Informed health policy, establishment of multi-disciplinary latex advisory committees overseeing purchasing practices and changing practices within institutions have all assisted in reducing sensitization and risks. Careful attention to hand hygiene and lowering the incidence of hand dermatitis in the workplace has also been instrumental in this regard.
For the latex-allergic individual, a number of precautions are needed. The major risks for these people are dipped rubber products such as NRL gloves, condoms, balloons, catheters and any medical device containing latex coming into contact with mucosal surfaces. Sensitized health care workers should use non-latex gloves at all times and their co- workers must use non-powdered gloves if NRL gloves are to be worn in the same space. If occupational latex-induced asthma has occurred it is essential to remove the worker from any workplace where latex particle exposure remains a possibility. Careful attention should be given to eliminating hand dermatitis. Spina bifida patients and those with similar problems must continue to avoid latex products from the outset.
A number of strongly advisable measures are indicated for the latex-allergic individual including appropriate notification of latex allergy on all medical and dental records; medical alert jewellery should be worn; a supply of non-latex gloves to be carried; epinephrine(adrenaline) auto injector prescribed with instructions of how and when to administer along with an anaphylaxis action plan.
The latex “epidemic” was a hugely costly occurrence to both the health care industry and the sensitised individual. Loss of highly trained professionals such as doctors, dentists and nurses from the workforce because of latex allergy, resulted in loss of millions of dollars in lost productivity and retraining, not to count the personal loss to these people. Carefully designed and monitored institutional policies and continuing collaborations between government agencies, healthcare sector and individuals has helped to turn around this epidemic. Unfortunately, there are still developing countries where latex allergy remains a significant problem and the advent of the Covid pandemic has changed glove ordering practices, once again increasing the possibility of further sensitization in vulnerable communities.
The following references are provided for additional information:
- Turjanmaa K. Incidence of immediate allergy to latex gloves in hospital personnel. Contact Dermatitis 1987;17:270
- Sussman G,Gold M. Guidelines for the Management of latex allergies and safe latex use in health care facilities. Am College of Allergy Asthma and Immunology 1996.
- American Latex Allergy Association www.allergyresources.org
- Hamilton RG, Brown RH. Impact of personal avoidance practices on health care workers sensitised to natural rubber latex. J Allergy Clin Immunol 2000;105:839.
- Kelly KJ, Sussman G. Latex Allergy: Where Are We Now and How Did We Get There? J Allergy Clin Immunol Pract 2017; 5:1212
- Phaswana SM,NaidooS. The prevalence oof latex senstisiation and allergy and associated risk factors among healthcare workers using hypoallergenic latex gloves at King Edward VIII Hospital. KwaZulu-Natal South Africa: a cross-sectional study. BMJ Open2013;3:e002900.
- Seyfarth F, SchliemannS, Wiegand C et al. Diagnostic value of the ISAC allergy chip in detecting latex sensitisations. Int Arch Occup Environ Health 2014;87:775.
- Van Kampen V,de Blay F,Folletti I et al. Evaluation of commercial skin prick test solutions for selected occupational allergens. Allergy 2013;68:651.
- Habib MAH,Ismail MN. Heavea brasiliensis latex proteomics:a review of analytical methods and the way forward.J Plant Res 2021;134:43