Latex Allergy
- Article Author:
- Khoa Nguyen
- Article Editor:
- Arpan Kohli
- Updated:
- 7/13/2020 11:09:21 PM
- For CME on this topic:
- Latex Allergy CME
- PubMed Link:
- Latex Allergy
Introduction
Latex comes from a sap found in rubber trees, Hevea brasiliensis, which is used to make many products we use today.[1][2] Latex is ubiquitous in health care, making up much of the equipment used, including catheters, balloons, and most commonly, gloves.[3][4][5] There have been hundreds of allergens identified from natural rubber latex (NRL) with 15 official ones given numbers (Hev b1 to Hev b15).[6][7][8] The natural proteins in rubber are associated with both asymptomatic sensitization and type I IgE-mediated hypersensitivity.[2] During latex processing, chemical antioxidants are added, which can cause type IV hypersensitivity reactions as well. Latex allergy is among the most common causes of anaphylaxis in the operating room and has increased in prevalence with the increased use of latex gloves to prevent transmittable infections starting in the 1980s.[7][9][8] A significant increase in the production of latex gloves has resulted in a widespread occurrence of allergies to latex.[9] Latex allergy has also become a well-known problem among healthcare workers while wearing gloves or inhaling aerosolized particles.
Etiology
Individuals in health care, including physicians, nurses, and dentists and those who work with chemicals or in labs, wear gloves more frequently than the general public. Many medical items contain latex besides gloves and include:
- Stethoscopes
- Catheters
- IV tubing
- Tourniquets
- Electrode pads
- Syringes
- Respirators
- Dental dams
- Drainage tubes
- Condoms
This increased exposure to latex puts them at risk for sensitization initially and ultimately, a latex allergy if sensitization continues. Direct exposure to the allergen through the use of gloves, condoms, or catheters is the most common cause of latex allergy with a direct correlation of sensitization to the amount of exposure.[8] Proteins can be transferred from gloves to the skin directly or can contaminate food from food handlers, resulting in a reaction in those who are already sensitized.[10] Aside from direct exposure to the allergen, individuals with certain food allergies are at higher risk of latex reactions. Allergies to fresh fruits and vegetables such as avocado, banana, chestnut, kiwi, celery, and pear cause patients to have a higher likelihood of hypersensitivity to latex. Those with latex allergy also have a higher sensitivity to those fruits and vegetables.[8][2][9]
Airborne particles are another source of allergen exposure as latex can be inhaled into the lungs. Cornstarch particles in latex gloves and tire dust are the most common sources of inhaled particles resulting in latex reactions.[8]
Epidemiology
There have been varying reports of the prevalence of latex allergy among the general population. Latex allergy affects 1 to 2 percent of the population, and one study showed that latex sensitization is more likely in health-care workers exposed to latex compared to the general population. Clinical manifestation, however, was approximately the same in both health-care workers and the general population.[4] In developing countries, there are more cases of latex allergy, as more latex products are in use.[10][2] Latex results in the most common cause of contact urticaria in occupational health as well as the second most common cause of intraoperative anaphylaxis, second to muscle relaxants.[10]
Epidemiologic studies have shown that a specific patient population such as those with spina bifida are at increased risk of developing a latex allergy with the prevalence of spina bifida hypersensitivity ranging from 20% to 65%.[2][8][10] The hypersensitivity is likely related to latex exposure from numerous corrective surgeries and procedures.[4] Patients with repeated catheterization due to urological abnormalities are also at increased risk.[8]
Pathophysiology
Latex has several modes of entry, including direct contact with the skin, entrance through mucous membranes or intravenously, or inhalation of latex powder through the lungs. A true latex allergy will result in a type I hypersensitivity reaction mediated by IgE antibodies that bind to the allergenic proteins. The binding causes the release of histamine, leukotrienes, prostaglandins, and kinins from mast cells and basophils, resulting in an immune response. Within minutes of exposure to latex, the patient may experience hives, wheezing, runny nose, and conjunctivitis.[2]
History and Physical
A thorough history and physical is necessary for the identification of patients with latex allergy. Patients likely to have symptoms are those with repeated exposure in health care or those in labs, specific food allergies, spina bifida, and frequent surgeries or procedures as a child. Latex allergy, however, can often be mistaken with an irritant or allergic contact dermatitis. Irritant contact dermatitis will result in erythema of the skin, whereas allergic contact dermatitis is due to a delayed-type IV hypersensitivity reaction. Patients with allergic dermatitis will also develop erythema, but will also have pruritus and urticaria after exposure; this is not a true latex allergy, and using nonlatex products could still result in the same reaction.[4]
A true latex allergy will result in type I immediate hypersensitivity reaction. This reaction will also result in itchy skin and urticaria, but could also present with angioedema, asthma, and systemic reactions, including anaphylaxis.[8][10][5]. Workers that use gloves, including those in health care, most commonly have allergic rhinitis and asthma due to inhalation of particles. Patients in the operating room will typically have a rash and bronchospasm, but most commonly present with cardiovascular collapse.[10]
Evaluation
Latex allergy diagnosis begins with a thorough history with a correlation of physical signs and symptoms. There are, however, several diagnostic tests, including serum testing and the skin prick test. The most common serum testing worldwide detects bound IgE using an enzymatic reagent in an in-vitro assay. However, results had significant false positives.[2][4] Skin prick testing is the other alternative, which is an in-vivo assay that involves pricking the skin and application of a non-ammoniated latex extract followed by close monitoring of wheal formation. Skin prick testing is considered the gold standard for diagnosing a type I hypersensitivity to latex; however, it is not available in the United States due to the lack of an approved natural rubber latex reagent.[4]
Treatment / Management
The most crucial step in managing patients who are susceptible to latex allergy is to determine individuals at high-risk through history and physical. After the determination of patients at risk for latex allergy, prevention of exposure is essential. However, if the individual is exposed and symptomatic, treatment is necessary depending on the type of reaction. If it is due to irritant dermatitis, removal of the latex and cleansing of the area is the first step. The application of topical steroids is used to reduce inflammation, and evaluation from a dermatologist is recommended. Delayed type IV hypersensitivity reactions have the same treatment, although the recommendation is to obtain testing for serum IgE as well. Patients with an immediate type I systemic reaction should have the exposure removed and undergo monitoring and treatment for life-threatening conditions. Management should begin with screening for high-risk individuals and the prevention of exposure. There are alternatives to latex such as neoprene, polyvinyl chloride, silicone, and vinyl and introduction of powder and latex-free gloves have significantly reduced the prevalence of latex allergies.[8][10][4]
Differential Diagnosis
Irritant contact dermatitis can present similarly to a latex allergy and can be mistaken for an allergic reaction when it is, in fact, a nonimmunologic reaction. This type of reaction is due to friction or contact with chemicals resulting in irritated skin. Individuals with these reactions do not have a true latex allergy and may not develop a response to latex. These patients will need a protective barrier for their skin and do not necessarily need to avoid latex exposure.[4]
Prognosis
There is currently no cure for latex sensitization or allergic reactions. Symptoms such as skin irritation are readily treatable with steroid creams, but prevention is the mainstay in decreasing the incidence of latex allergies.[2] Proper patient education with information on products containing latex and alternatives to those products will be necessary for avoidance. It is also essential for patients when admitted to the hospital to clearly state that they have a latex allergy.[10] Patients with proper education and prevention will have positive outcomes, but without appropriate prevention, patients will continue to have symptoms and may have their quality of life significantly affected.[11]
Complications
Patients who have more frequent exposure or have had heavy sensitization to latex have a higher risk of anaphylaxis.[10] This reaction can lead to severe multiorgan involvement, including airway compromise and cardiovascular collapse, leading to cardiopulmonary arrest. Treatment of anaphylaxis requires removal of the allergen, airway protection, early epinephrine administration, and fluid resuscitation.[12]
Deterrence and Patient Education
Education is crucial for the prevention of allergic reactions. Patients require training regarding foods likely to cause cross-reactions with latex sensitivity and any products that contain latex. It is also important to notify any members of the health-care team involved with caring for the patient that there is an allergy. Patients must receive alternatives to latex products, and proper compliance will result in decreased risk of reactions.[10]
Enhancing Healthcare Team Outcomes
Prevention is crucial in good outcomes for patients with latex allergy. Because of the widespread allergy to latex in the healthcare environment, there is now an interprofessional team that now only sets policies on purchasing latex-free products but assists with the management of latex-sensitive patients.
Ancillary staff, technicians, nurses, and physicians involved in caring for the patient are the first line in the prevention of incidental exposure to latex for the patient on admission to the hospital. If they have symptoms, an allergist and immunologist will help determine if there are sensitization and a true latex allergy.
Elimination of latex products has been shown to reduce the problem with a marked reduction in healthcare costs. Nurses are often the first to see patients and should be taught to determine the presence of latex allergy in the patient history, which enables healthcare workers to provide a latex-free environment. Lastly, if there are persistent symptoms, a dermatologist could be consulted to aid in the treatment.[2] In the event of allergic reaction or anaphylaxis, the pharmacist is a valuable team resource to recommend and prepare medications needed to combat such a reaction, ranging from steroid therapies to epinephrine injection. Only through this type of collaborative interprofessional approach can latex allergies be reduced in frequency or managed most effectively when they occur. [Level 5]