Latex allergy

# Overview
Latex allergy is a medical term encompassing a range of allergic reactions to natural rubber latex.

# Types
Latex is known to cause 2 of the 4 (or 5) types of hypersensitivity:

## Type I
Latex allergy (immediate hypersensitivity) can be a more serious reaction (the most serious and rare form) to latex than irritant contact dermatitis or allergic contact dermatitis. Certain proteins in latex may cause sensitization (positive blood or skin test, with or without symptoms). Although the amount of exposure needed to cause sensitization or symptoms is not known, exposures at even very low levels can trigger allergic reactions in some sensitized individuals.
Reactions usually begin within minutes of exposure to latex, but they can occur hours later and can produce various symptoms. Mild reactions to latex involve skin redness, hives, or itching. More severe reactions may involve respiratory symptoms such as runny nose, sneezing, itchy eyes, scratchy throat, and asthma (difficult breathing, coughing spells, and wheezing). Rarely, shock may occur; but a life-threatening reaction is seldom the first sign of latex allergy. Reactions are similar to those seen in some allergic persons after a bee sting.
Such reactions account for a significant proportion of perioperative anaphylactic reaction, especially in children with myelomeningocele.

## Type IV
Allergic contact dermatitis (delayed hypersensitivity, also sometimes called chemcial sensitivity dermatitis) results from exposure to chemicals added to latex during harvesting, processing, or manufacturing.
These chemicals can cause skin reactions similar to those caused by poison ivy (see urushiol-induced contact dermatitis). As with poison ivy, the rash usually begins 24 to 48 hours after contact and may progress to oozing skin blisters or spread away from the area of skin touched by the latex.
This type is caused by chemicals used in the processing of rubber products.

## Irritant contact dermatitis
The most common type of reaction. This causes dry, itchy, irritated areas on the skin, most often on the hands.  It can be caused by the irritation of using gloves, or it can also be caused by exposure to other workplace products.  Frequent washing of the hands, incomplete drying, exposure to hand sanitizers, and the talc-like powder coatings (zinc oxide, etc) used with gloves can aggravate symptoms. Irritant contact dermatitis is not a true allergy.
Testing for type I natural rubber latex allergy is through blood testing, such as RAST (radioallergosorbent test) identifies what types of IgE proteins trigger allergic reactions.  While the standard for allergen testing is the skin prick test, there is no approved skin testing reagent for latex in the United States at this time.  Some other countries do have approved skin testing reagents for natural rubber latex.  Some people who are allergic to latex are also allergic to clothes, shoes and other things that contain natural rubber latex - for example elastic bands, rubber gloves, condoms, pacifiers and baby-bottle nipples, balloons, cars and clothing containing natural rubber based elastic. Synthetic elastic such as elastane or neoprene do not contain the proteins that trigger type I reactions. Type I natural rubber latex allergy is caused from IgE (immune) mediated reactions to proteins found in the Hevea brasiliensis tree, a type of rubber tree. Synthetic latex products do not contain the proteins from the Hevea brasiliensis tree and will not cause this type of reaction. Products made from guayule natural rubber emulsions also do not contain the proteins from the Hevea rubber tree and have only trace amounts of other proteins, indicating a very low potential for causing sensitization to this material.
Type IV reactions are caused by the chemicals used to process the rubber. Patch testing needs to be done to verify which type of chemical triggers the reaction. Once the chemical is identified, then the person can choose products that are not processed with that chemical. Both natural rubber and synthetic rubber products may cause type IV reactions.

# Products Containing Latex
A wide variety of products contain latex: medical supplies, personal protective equipment, and numerous household objects. Most people who encounter latex products only through their general use in society have no health problems from the use of these products. Workers who repeatedly use latex products are the focus of this Alert. The following are examples of products that may contain latex:

## Emergency  Equipment
- Blood pressure cuffs
- Stethoscopes
- Disposable gloves
- Oral and nasal airways
- Endotracheal tubes
- Tourniquets
- Intravenous tubing
- Syringes
- Electrode pads

## Personal Protective Equipment
- Gloves
- Surgical masks
- Goggles
- Respirators
- Rubber aprons

## Office Supplies
- Rubber bands
- Erasers

## Hospital Supplies
- Anesthesia masks
- Catheters
- Wound drains
- Injection ports
- Rubber tops of multidose vials
- Dental dams

## Household Objects
- Automobile tires
- Motorcycle and bicycle handgrips
- Carpeting
- Swimming goggles
- Racquet handles
- Shoe soles
- Expandable fabric (waistbands)
- Dishwashing gloves
- Hot water bottles
- Condoms
- Diaphragms
- Balloons
- Pacifiers
- Baby bottle nipples
Individuals who already have latex allergy should be aware of latex-containing products that may trigger an allergic reaction. Some of the listed products are available in latex-free forms.

## Latex in the Workplace
Workers in the health care industry (physicians, nurses, dentists, technicians, etc.) are at risk for developing latex allergy because they use latex gloves frequently. Also at risk are workers with less frequent glove use (hairdressers, housekeepers, food service workers, etc.) and workers in industries that manufacture latex products.

# Levels and Route of Exposure
Studies of other allergy-causing substances provide evidence that the higher the overall exposure in a population, the greater the likelihood that more individuals will become sensitized  The amount of latex exposure needed to produce sensitization or an allergic reaction is unknown; however, reductions in exposure to latex proteins have been reported to be associated with decreased sensitization and symptoms  
The proteins responsible for latex allergies have been shown to fasten to powder that is used on some latex gloves. When powdered gloves are worn, more latex protein reaches the skin. Also, when gloves are changed, latex protein/powder particles get into the air, where they can be inhaled and contact body membranes  In contrast, work areas where only powder-free gloves are used show low levels or undetectable amounts of the allergy-causing proteins  
Wearing latex gloves during episodes of hand dermatitis may increase skin exposure and the risk of developing latex allergy. The risk of progression from skin rash to more serious reactions is unknown. However, a skin rash may be the first sign that a worker has become allergic to latex and that more serious reactions could occur with continuing exposure 

# Those at greatest risk
- Children with myelomeningocele Spina bifida.  Between 40% to 100% will have a reaction.
- Industrial rubber workers, exposed for long periods to high amounts of latex.  About 10% have an allergic reaction.
- Healthcare workers.  Given the ubiquitous use of latex products in health care settings, management of latex allergy presents significant health organizational problems. Healthcare workers who frequently use latex gloves and other latex-containing medical supplies such as physicians, nurses, aides, dentists, dental hygienists, operating room employees, laboratory technicians, and hospital housekeeping personnel are at risk for developing latex allergy.  Between about 4% to 17% of healthcare workers have a reaction, this usually presents as Irritant Contact Dermatitis, and can develop through allergic sensitivity to a status of full anaphylaxis shock; with health workers losing their vocation.  In the surgical setting, however, the risk of a potentially life-threatening allergic reaction by a patient has been deemed by Johns Hopkins Hospital to be sufficiently high to replace all latex surgical gloves with synthetic alternatives.
- People who have had multiple surgical procedures, especially in childhood.
Estimates of latex sensitivity in the general population range from 0.8% to 8.2%, although not all will ever develop a noticeable allergic reaction.

# Latex and foods
Some people who have latex allergy may also have an allergic response to any of a number of plant products, usually fruits.  This is known as the latex-fruit syndrome.  Fruits (and seeds) involved in this syndrome include banana, pineapple, avocado, chestnut, kiwi fruit, mango, passionfruit, strawberry, and soy.  Some but not all of these fruits contain a form of latex.  The Asthma and Allergy Foundation of America estimates that nearly 6 percent of the United States population have some type of food allergy and up to 4 percent have an allergy to latex. It can also cause reactions from foods touched by latex products in the most severe cases. There are some known cases of latex allergies being provoked from genetically modified foods such as tomatoes with latex proteins.
Some individuals who are highly allergic to latex have had allergic reactions to foods that were handled or prepared by people wearing latex gloves.

# Diagnosing Latex Allergy
Latex allergy should be suspected in anyone who develops certain symptoms after latex exposure, including nasal, eye, or sinus irritation; hives; shortness of breath; coughing; wheezing; or unexplained shock. Any exposed worker who experiences these symptoms should be evaluated by a physician, since further exposure could result in a serious allergic reaction. A diagnosis is made by using the results of a medical history, physical examination, and tests.
Taking a complete medical history is the first step in diagnosing latex allergy. In addition, blood tests approved by the Food and Drug Administration (FDA) are available to detect latex antibodies. Other diagnostic tools include a standardized glove-use test or skin tests that involve scratching or pricking the skin through a drop of liquid containing latex proteins. A positive reaction is shown by itching, swelling or redness at the test site. However, no FDA-approved materials are yet available to use in skin testing for latex allergy. Skin testing and glove-use tests should be performed only at medical centers with staff who are experienced and equipped to handle severe reactions.
Testing is also available to diagnose allergic contact dermatitis. In this FDA-approved test, a special patch containing latex additives is applied to the skin and checked over several days. A positive reaction is shown by itching, redness, swelling, or blistering where the patch covered the skin.
Occasionally, tests may fail to confirm a worker who has a true allergy to latex, or tests may suggest latex allergy in a worker with no clinical symptoms. Therefore, test results must be evaluated by a knowledgeable physician.

# Treating Latex Allergy
Once a worker becomes allergic to latex, special precautions are needed to prevent exposuresduring work as well as during medical or dental care.
Certain medications may reduce the allergy symptoms, but complete latex avoidance (though quite difficult) is the most effective approach. Many facilities maintain latex-safe areas for affected patients and workers.

# Case Reports
The following case reports briefly describe the experiences of six workers who developed latex allergy after occupational exposures. These cases are not representative of all reactions to latex but are examples of the most serious types of reactions. They illustrate what has occurred in some individuals.

## Case No. 1
A laboratory technician developed asthma symptoms after wearing latex gloves while performing blood tests. Initially, the symptoms occurred only on contact with the gloves; but later, symptoms occurred when the technician was exposed only to latex particles in the air. 

## Case No. 2
A 33-year-old woman sought medical treatment for occupational asthma after 6 months of periodic cough, shortness of breath, chest tightness, and occasional wheezing. She had worked for 7 years as an inspector at a medical supply company, where her job included inflating latex gloves coated with cornstarch. Her symptoms began within 10 minutes of starting work and worsened later in the day (90 minutes after leaving work). Symptoms disappeared completely while she was on a 12-day vacation, but they returned on her first day back at work. 

## Case No. 3
A nurse developed hives in 1987, nasal congestion in 1989, and asthma in 1992. Eventually she developed severe respiratory symptoms in the health care environment even when she had no direct contact with latex. The nurse was forced to leave her occupation because of these health effects. 

## Case No. 4
A midwife initially suffered hives, nasal congestion, and conjunctivitis. Within a year, she developed asthma, and 2 years later she went into shock after a routine gynecological examination during which latex gloves were used. The midwife also suffered respiratory distress in latex-containing environments when she had no direct contact with latex products. She was unable to continue working.

## Case No. 5
A physician with a history of seasonal allergies, runny nose, and eczema on his hands suffered severe runny nose, shortness of breath, and collapse minutes after putting on a pair of latex gloves. He was successfully resuscitated by a cardiac arrest team 

## Case No. 6
An intensive care nurse with a history of runny nose, itchy eyes, asthma, eczema, and contact dermatitis experienced four severe allergic reactions to latex. The first reaction began with asthma severe enough to require treatment in an emergency room. The second and third reactions were similar to the first. The fourth and most severe reaction occurred when she put on latex gloves at work. She went into severe shock and was successfully treated in an emergency room 

# Recommendations
The following recommendations for preventing latex allergy in the workplace are based on current knowledge and a common-sense approach to minimizing latex-related health problems. Evolving manufacturing technology and improvements in measurement methods may lead to changes in these recommendations in the future. For now, adoption of the recommendations wherever feasible will contribute to the reduction of exposure and risk for the development of latex allergy.

## Employers
Latex allergy can be prevented only if employers adopt policies to protect workers from undue latex exposures. NIOSH recommends that employers take the following steps to protect workers from latex exposure and allergy in the workplace:
- Provide workers with nonlatex gloves to use when there is little potential for contact with infectious materials (for example, in the food service industry).
- Appropriate barrier protection is necessary when handling infectious materials . If latex gloves are chosen, provide reduced protein, powder-free gloves to protect workers from infectious materials. The goal of this recommendation is to reduce exposure to allergy-causing proteins (antigens). Until well accepted standardized tests are available, total protein serves as a useful indicator of the exposure of concern.
- Ensure that workers use good housekeeping practices to remove latex-containing dust from the workplace:
- Identify areas contaminated with latex dust for frequent cleaning (upholstery, carpets, ventilation ducts, and plenums).
- Make sure that workers change ventilation filters and vacuum bags frequently in latex-contaminated areas.
- Provide workers with education programs and training materials about latex allergy.
- Periodically screen high-risk workers for latex allergy symptoms. Detecting symptoms early and removing symptomatic workers from latex exposure are essential for preventing long-term health effects.
- Evaluate current prevention strategies whenever a worker is diagnosed with latex allergy.

## Workers
Workers should take the following steps to protect themselves from latex exposure and allergy in the workplace:
- Use nonlatex gloves for activities that are not likely to involve contact with infectious materials (food preparation, routine housekeeping, maintenance, etc.).
- Appropriate barrier protection is necessary when handling infectious materials . If you choose latex gloves, use powder-free gloves with reduced protein content:
- Such gloves reduce exposures to latex protein and thus reduce the risk of latex allergy (though symptoms may still occur in some workers).
- So-called hypoallergenic latex gloves do not reduce the risk of latex allergy. However, they may reduce reactions to chemical additives in the latex (allergic contact dermatitis).
- Use appropriate work practices to reduce the chance of reactions to latex:
- When wearing latex gloves, do not use oil-based hand creams or lotions (which can cause glove deterioration) unless they have been shown to reduce latex-related problems and maintain glove barrier protection.
- After removing latex gloves, wash hands with a mild soap and dry thoroughly.
- Use good housekeeping practices to remove latex-containing dust from the workplace:
- Frequently clean areas contaminated with latex dust (upholstery, carpets, ventilation ducts, and plenums).
- Frequently change ventilation filters and vacuum bags used in latex-contaminated areas.
- Take advantage of all latex allergy education and training provided by your employer:
- Become familiar with procedures for preventing latex allergy.
- Learn to recognize the symptoms of latex allergy: skin rashes; hives; flushing; itching; nasal, eye, or sinus symptoms; asthma; and shock.
- If you develop symptoms of latex allergy, avoid direct contact with latex gloves and other latex-containing products until you can see a physician experienced in treating latex allergy.
- If you have latex allergy, consult your physician regarding the following precautions:
- Avoid contact with latex gloves and other latex-containing products.
- Avoid areas where you might inhale the powder from latex gloves worn by other workers.
- Tell your employer and your health care providers (physicians, nurses, dentists, etc.) that you have latex allergy.
- Wear a medical alert bracelet.
- Carefully follow your physician's instructions for dealing with allergic reactions to latex.