VIRUSMYTH HOMEPAGE


LATEX ALLERGY

March 2000

Authored by Amy J Behrman, MD, Director, Occupational Medicine, Assistant Professor, Department of Emergency Medicine, University of Pennsylvania Medical Center

Amy J Behrman, MD, is a member of the following medical societies: American College of Occupational arid Environmental Medicine, and American Public Health Association

Edited by Mark Louden, MD, FAAEM, Consulting Staff, Department Of Emergency Medicine, Saint Francis Medical Center; Francisco Talavera, PharmD, PhD, Department of Pharmacy, Creighton University; Matthew M Rice, MD, JD, Chair, Department of Emergency Medicine, Madigan Army Medical Center; John Halamka, MD, chief Information Officer/CareGroup Healthcare System, Assistant Professor of Medicine, Department of Emergency Medicine, Beth Israel Deaconess Medical Center; and Craig Feied, MD, FACEP, FAAEM, Director of National Center for Emergency Medicine Informatics, Clinical Associate Professor, Department of Emergency Medicine, Washington Hospital Center

INTRODUCTION

Background:

Allergy to natural rubber latex is increasingly common and serious in pediatric and adult populations. Latex is the milky fluid derived from the lactiferous cells of the rubber tree, Hevea brasiliensis. Latex is primarily composed of cis 1,4-polyisoprene, a benign organic polymer that confers most of the strength and elasticity of latex. It also contains a large variety of sugars, lipids, nucleic acids, and highly allergenic proteins.

The protein content varies with harvest location and manufacturing processes. Basic knowledge of the manufacturing processes aids in understanding the medical problems related to latex exposure.

Freshly harvested latex from Malaysia, Indonesia, Thailand, and South America is treated with ammonia and other preservatives to prevent deterioration during transport to factories. Latex is treated with antioxidants and accelerators including thiurams, carbamates, and mercaptobenzothiazoles. It is then shaped into the desired object and vulcanized to produce disulfide cross-linking of latex molecules.

After being dried and rinsed to reduce proteins and impurities, the product frequently is dry lubricated with cornstarch or talc powder. Powder particles rapidly adsorb residual latex proteins; other proteins remain in soluble form on the surface of finished products.

Latex is ubiquitous in modern society and, particularly, in health care. William Halstead first used latex surgical gloves in 1890. Latex has been used in a myriad of medical devices for decades. In the late 1980s, however, its use skyrocketed as latex gloves were widely recommended to prevent transmission of blood-borne pathogens, including the human immunodeficiency virus (HIV). Eight billion pairs of medical gloves were imported to the US in 1988, primarily as powdered, non-sterile examination gloves.

The pressure that was placed on manufacturing companies resulted in hundreds of new, poorly regulated latex factories in tropical countries. The incidence of minor and serious allergic reactions to latex began to rapidly rise among patients and health care workers (HCWs).

Latex sensitization can occur after skin or mucosal contact, peritoneal contact during surgery, or inhalation of aerosolized particles with latex on their surfaces.

Pathophysiology:

Latex is associated with 3 clinical syndromes.

The first syndrome is irritant dermatitis. It is due to chronic latex exposure and accounts for the majority of local skin rashes. It is not immune-mediated, is not associated with allergic complications, and is not the subject of this chapter. It may be confused with Type IV hypersensitivity. Any chronic hand dermatitis in HCWs raises the risk of nosocomial infections, including blood-borne pathogens.

The second syndrome is a delayed (Type IV) hypersensitivity reaction, resulting in a typical contact dermatitis. Symptoms usually develop within 24-48 hours of cutaneous or mucous membrane exposure to latex in a sensitized person. The primary allergens are residual accelerators and antioxidants left from the original manufacturing process. Langerhans cells process the antigens and present them to cutaneous T-cells. Multiple objects can cause sensitization, but the most common sources in this country are probably examination gloves for adults and shoe soles for children. Type IV hypersensitivity is more common in atopic individuals. The dermatitis may predispose patients to further sensitizations or infections.

The third, most serious, and least common, syndrome is the immediate (Type I) hypersensitivity. It is mediated by an IgE response specific for latex proteins. As noted, latex proteins are highly allergenic, and they are variable between lots from different plantations, factories, and manufacturers. Cross-linking of IgE molecules on mast cell and basophil cell membranes by latex protein allergens triggers the release of histamine and other mediators of the systemic allergic cascade in sensitized individuals. Exposure can occur following skin, mucous membrane, or visceral/peritoneal contact. It also can follow inhalation of latex laden particles or blood stream exposure to soluble latex proteins following intravascular access procedures. Powdered latex examination gloves are the most frequent source of sensitization in adults, causing cutaneous and inhalational exposures. Sensitization is more common in atopic individuals. Symptoms generally begin within minutes of exposure. The spectrum of clinical manifestations includes localized or generalized urticaria, rhinitis, conjunctivitis, bronchospasm, laryngospasm, hypotension, and full-blown anaphylaxis. Type I allergy has been clearly implicated in intraoperative and intraprocedure anaphylaxis, and it can be fatal without emergent treatment.

Frequency:

In the US:

Latex allergy is present in 1-5% of the general population, with an increased prevalence in atopic individuals. Latex allergy is increased in populations with chronic occupational exposure to latex. It is found in 10-30% of HCWs and in at least 10% of rubber industry workers. Symptoms of latex allergy have been described in 14% of a group of EMS providers and in 54% of a pediatric ED staff. Atopy raises the risk of occupational sensitization.

The highest prevalence of latex allergy (20-68%) is found in patients with spina bifida or congenital urogenital abnormalities. Sensitization in these patients apparently follows multiple urinary tract, rectal and thecal procedures, as well as multiple surgeries during early childhood. Again, within this risk group, atopic children are at increased risk. Other patients with a history of multiple surgeries or other latex-exposing procedures are also at increased risk relative to the general population. Patients with cerebral palsy, mental retardation, and quadriplegia also appear to have increased risk of latex allergy, probably due to multiple medical exposures.

Finally, the prevalence of latex allergy is increased in persons with allergies to avocado, banana, chestnut, kiwi, papaya, peach, and nectarine. Cross-reacting antigens have been found between these fruits and latex.

Internationally:

The risk patterns described above are similar in other developed countries. One study from Germany suggests that the incidence of Type I latex allergy has risen faster recently among HCWs than Type IV hypersensitivity, possibly due to recent manufacturing changes that lessen exposure to accelerators, but not to latex proteins. Workers with occupational exposure in undeveloped countries, where H. brasiliensis is grown, have an increased risk relative to the general populations.

Mortality/Morbidity:

Patients with Type I hypersensitivity are at risk for developing anaphylaxis and/or respiratory obstruction, which can be fatal.

Deaths have been reported following the intraoperative use of latex rectal catheters. Latex anaphylaxis has occurred after childbirth, instrumentation, intravenous injection, balloon blowing, and condom use.

Although most patients can be treated effectively for Type IV and Type I reactions without clinical sequelae, major allergy may prevent them from pursuing careers, using many household and workplace objects, and seeking timely medical care due to justified fear of latex exposure.

Sex:

Male = Female

Age:

Latex allergy probably is more common in children and in younger working adults due to the increased medical and/or occupational exposure over the past decade.

CLINICAL

History:

Symptoms of delayed (Type IV) hypersensitivity usually develop within 1-2 days of exposure. Immediate (Type I) hypersensitivity causes symptoms within minutes of exposure. Symptoms may include the following:

  • Pruritus of exposed skin and mucous membranes
  • Edema of the skin, mucous membranes, or subcutaneous tissues
  • Hoarseness
  • Tearing
  • Rhinitis
  • Dyspnea
  • Lightheadedness, syncope
  • Abdominal cramping
  • Nausea, vomiting
  • Diarrhea

Physical:

  • Rash
  • Erythema, edema, papules, and vesicles in areas of direct contact (Type IV)
  • Erythema, thickening, and pigment changes with chronic exposure (Type IV)
  • Urticaria, localized or generalized (Type I)
  • Angioedema
  • Conjunctivitis
  • Rhinitis
  • Stridor
  • Wheezing
  • Hypotension, shock

Causes:

The source of latex exposure may be obvious or occult. The history of latex allergy may be known or unknown. Medical procedures may cause reactions in sensitized providers or patients. Inadvertent inhalational exposure is frequent in medical settings where aerosolized latex-laden glove powder may remain airborne for hours. Inhalational exposure also may occur outside hospitals from use of powder-lubricated latex products or even tire particles in heavy traffic areas. Common sources of latex exposure include, but are not limited to, the following:

  • Gloves (e.g., examination, surgical, or household)
  • Airways (e.g., oral, nasal, or endotracheal)
  • Tourniquets, blood pressure cuffs
  • Stethoscopes
  • Catheters
  • Intravenous tubing ports, syringe plungers
  • Electrode pads
  • Goggles
  • Respirators
  • Wound drains and tubes
  • Multidose vial tops
  • Dental dams
  • Tires
  • Handgrips
  • Carpeting
  • Shoe soles, elastic in clothing
  • Condoms, diaphragms
  • Balloons
  • Pacifiers, baby bottle nipples
  • Erasers, computer mouse pads, and rubber bands

DIFFERENTIALS

Anaphylaxis
Angioedema
Asthma
Conjunctivitis
Dermatitis, Atopic
Dermatitis, Contact
Pediatrics, Anaphylaxis
Shock, Cardiogenic
Shock, Septic

WORKUP

Lab Studies:

ED diagnosis and management depends on the history and the physical examination. Results of laboratory tests sent from the ED will not be available in a useful time frame. Several types of study are useful in non-emergent evaluations.

Total serum IgE may be elevated in patients with Type I allergy, but it is neither sensitive nor specific.

Radioimmunoassay tests (RAST) for IgE, which specifically bind latex antigens, range from 50-100% sensitive and 63-100% specific. Predictive value depends on the exact test used, the patient population, and the source of allergen. RAST can be a useful and safe confirmatory test in patients with suggestive clinical histories.

Enzyme linked assays of latex-specific IgE (ELISA) may serve the same purpose.

Other Tests:

Skin patch testing is useful in identifying specific allergens in patients with Type IV hypersensitivity to latex products.

Skin prick testing with latex extracts is sensitive, specific, and rapid; however, it carries the risk of anaphylaxis. No standardized extracts are licensed in the US.

Testing with glove fingertips applied to the patient's skin is useful when the history is consistent with latex allergy, but the blood tests are negative. It carries the risk of anaphylaxis in Type I-sensitized patients.

Procedures:

If Type I latex allergy is suspected, all procedures should be performed with latex-free instruments, devices, and protective clothing.

TREATMENT

Prehospital Care:

Prehospital providers should be aware of the risk of latex allergy in patients and providers.

Search for and read MedicAlert-type bracelets.

Note the patient's history of relevant allergies to medical devices or fruits.

To rule out latex allergy that could worsen with further medical exposure, review the patient's history of activities/exposures immediately preceding any systemic allergic reaction.

Use powder-free latex gloves or, ideally, high-quality, nonlatex gloves to minimize risk to patients and providers. Latex-free resuscitation and IV equipment should be available for high-risk patients. Do not give medication from rubber-topped multidose vials or through latex IV ports in latex allergic patients.

Emergency Department Care:

Patients with known or suspected latex allergy who seek care for an unrelated medical condition or injury must be kept within a latex-safe environment to prevent serious complications. This includes all patients with a history of spina bifida.

Patients presenting with frank symptoms of Type I latex allergy are treated as any other patients with systemic allergic reactions, except they must be protected from further latex contact to avoid clinical deterioration. Many EDs represent very high-risk environments for latex-sensitive patients, particularly if powdered latex gloves are in use.

Latex-free resuscitation equipment must be available. This frequently is accomplished with a mobile, latex-free cart carrying non-latex intubation and ventilation equipment, IV tubing, syringes, tourniquets, electrode pads, gloves, masks, and medication vials.

Routine care of high-risk patients should employ nonlatex supplies. Major reactions in sensitized patients have been precipitated with pelvic and rectal exams using latex gloves, urinary catheterization with latex catheters, IV medication given through latex ports, and inhalation of aerosolized latex glove powder.

Consultants must be aware of the need to completely avoid latex exposure to the patient during exams and procedures.

Patients needing studies in other hospital areas, such as radiology, must be transported without risking latex exposure.

Identification of latex versus nonlatex medical devices has traditionally required laborious contacts with individual manufacturers. A new FDA policy will require all manufacturers to apply warning labels to products containing natural rubber latex. This will facilitate safe care of allergic patients.

Consultations:

Consultants must be aware of the need to completely avoid latex exposure to the patient during exams and procedures.

MEDICATION

Type IV hypersensitivity is best treated with patient education to avoid further exposure. Type I reactions are treated as any other systemic allergic reaction. The cornerstones of treatment are epinephrine and H1 antihistamines. Systemic corticosteroids and H2 blockers may be useful. Please see chapters on "Anaphylaxis," "Angioedema," and "Asthma" for details of therapy.

FOLLOW-UP

Further Inpatient Care:

Patients with major latex allergies who are admitted for allergic complications or unrelated conditions must be moved to a latex-safe room with clear warnings on both the door and the chart.

All examinations and care must be done without use of latex-containing devices or equipment.

All providers should be educated to avoid inadvertent exposure.

Further Outpatient Care:

Patients and their families should be educated to identify and avoid latex in home, work, and medical/dental settings.

Patients should be referred to an allergist or primary care provider for follow-up.

Patients should be aware of the life-threatening complications of anaphylaxis, bronchospasm, and laryngospasm.

Type I patients should carry subcutaneous epinephrine kits at all times.

Patients should obtain and wear a MedicAlert-type bracelet identifying their allergy.

Patients should be aware of cross-reacting fruit allergies.

In/Out Patient Meds:

See chapters on "Anaphylaxis," "Angioedema," and "Asthma" for inpatient and outpatient medications.

All patients with Type 1 latex allergy should carry a subcutaneous epinephrine kit at all times.

Deterrence/Prevention:

Hospitals should make policy and purchasing decisions to minimize latex exposure in the institution, with the goal being to protect sensitized patients and employees, as well as to reduce primary sensitization.

Minimally, this requires reducing or eliminating powdered latex exam gloves and substituting less allergenic latex gloves or, ideally, high-quality, nonlatex gloves.

It also requires clear guidelines for the safe treatment of sensitized patients and for the accommodation of sensitized employees.

Multidisciplinary hospital committees can be effective in accomplishing these goals.

Federal guidelines to reduce latex exposure will impact all hospitals in the near future.

Complications:

Respiratory compromise

Anaphylaxis

Prognosis:

Most latex allergic patients can function normally by avoiding significant latex exposure at home, at work, and in medical/dental situations.

Some patients will become more sensitized and have greater difficulty functioning.

A small percentage of patients with IgE-mediated allergy become so sensitized that inadvertent exposure to minute amounts of latex, either by contact or inhalation, causes frequent life-threatening episodes.

In the absence of effective immunomodulatory therapy, avoidance of latex and excellent ED care must be the patients' mainstays.

Patient Education:

Patients can and should be referred to local or national support groups to stay abreast of new developments in latex-free devices that may make their lives safer and more convenient.

These groups frequently maintain lists of latex-safe medical and dental practices, as well as tracking regulatory and legislative developments.

MISCELLANEOUS

Medical/Legal Pitfalls:

All EDs eventually will see patients with severe latex allergies. Inadvertent latex exposure to such a patient in the ED may result in adverse outcomes and litigation.

Failure to maintain latex-safe equipment in the ED may result in adverse outcomes and litigation.

Failure to obtain a history suggestive of recognized or unrecognized latex allergy may result in adverse outcomes and litigation.

Discharge without appropriate patient education may result in adverse outcomes and litigation.

Failure to comply with evolving federal regulations to decrease latex exposure to HCWs and patients may incur liability for an institution.

Institutional failure to accommodate latex-sensitized HCWs may lead to litigation.

TEST QUESTIONS

CME Question 1: Life-threatening hypersensitivity to latex is most likely in which patients?

A: Those who are allergic to kiwi fruit
B: Those who come from a country where rubber is produced
C: Those who were born with a myelomeningocele
D: Those who work in a hospital
E: Those who have seasonal rhinitis

The correct answer is C: Patients with any form of spina bifida are at enormously increased risk for systemic latex allergy. This most likely follows sensitization from multiple surgeries, urinary catheterizations, and ventriculoperitoneal shunting in early childhood. Although individuals from all the other groups are at increased risk for latex allergy, the prevalence is significantly less high.

CME Question 2: Latex sensitization in adults is most often due to which of the following?

A: Powdered latex gloves
B: Condoms
C: Avocado dip
D: Computer mouse pads
E: Automobile tire fragments

The correct answer is A: Latex proteins readily adsorb to cornstarch particles and can, thereby, cause sensitization through inhalation, as well as direct contact to skin or mucous membranes. Although the other items contain latex or latexlike proteins, exam gloves are the major source of latex sensitization in otherwise healthy adult populations.

Pearl Question 1 : How can patients with IgE-mediated latex allergy ensure the best prognosis?

The correct answer is : All such patients should wear a MedicAlert-type device, notify their medical/dental providers of their condition, strenuously avoid all possible latex contact or inhalation, and carry injectible epinephrine.

Pearl Question 2 : What tests or studies best identify latex allergic ED patients?

The correct answer is : The clinical history is more sensitive, specific, and safe than any test now available. In patients with a suggestive history, blood and skin tests may be helpful in establishing a firm diagnosis. However, these test results will take days to return.

Pearl Question 3 : How can patients and doctors know which products contain latex?

The correct answer is : New FDA regulations will require manufacturers to use a warning label on all products containing natural rubber latex. In the meantime, a basic knowledge of common devices/products with latex and a willingness to contact the manufacturer are needed. `Dry rubber` products and `latex` paint are not latex sources.

Pearl Question 4 : Do we really need latex-safe capability and latex-free equipment in the ED?

The correct answer is : Yes.

BIBLIOGRAPHY

Fein JA, Selbst SM, Pawlowski NA: Latex allergy in pediatric emergency department personnel. Pediatr Emerg Care 1996 Feb; 12(1): 6-9.

Landwehr LP, Boguniewicz M: Current perspectives on latex allergy [see comments]. J Pediatr 1996 Mar; 128(3): 305-12.

Melton AL: Managing latex allergy in patients and health care workers. Cleve Clin J Med 1997 Feb; 64(2): 76-82.

Woods JA, Lambert S, Platts-Mills TA: Natural rubber latex allergy: spectrum, diagnostic approach, and therapy. J Emerg Med 1997 Jan-Feb; 15(1): 71-85.

NOTE:

Medicine is a constantly changing science and not all therapies are clearly established. New research changes drug and treatment therapies daily. The authors, editors, and publisher of this textbook have used their best efforts to provide information that is up-to-date and accurate and is generally accepted within medical standards at the time of publication. However, as medical science is constantly changing and human error is always possible, the authors, editors, and publisher or any other party involved with the publication of this text do not warrant the information in this text is accurate or complete, nor are they responsible for omissions or errors in the text or for the results of using this information. The reader should confirm the information in this text from other sources prior to use. In particular, all drug doses, indications, and contraindications should be confirmed in the package insert.


VIRUSMYTH HOMEPAGE