Since the first report of contact urticaria to natural rubber products in
1979, a series of serious life-threatening allergic reactions has been
reported worldwide. In 1991, an alert from the Centers for Disease
Control and the Food and Drug Administration (FDA) in the USA
warned the public about anaphylaxis related to latex sensitivity
occurring during radiological and surgical procedures. Despite the
marked increase in this problem, physicians, nurses and patients, who
are most commonly affected, remain uninformed of this health hazard.
Case histories of patients presenting to the allergy clinic at the
Medical College of Wisconsin (see below)
illustrate the varied presentations and severity of
latex allergy; symptoms range from contact urticaria,
upper and lower airway allergy, to life-threatening
anaphylaxis. These patients are allergic to natural
latex protein as a result of exposure in their job or
through daily medical care.
Case History Summaries of Patients Presenting to the Allergy Clinic at the Medical College of Wisconsin
- Case 1
A 10-year-old patient with spina bifida, who had previously undergone 19 neurosurgical, orthopaedic and urological surgical procedures, developed severe wheezing, hypotension and generalized flushing accompanied required a 2-hour resuscitation until vital signs stabilized.
- Case 2
A surgeon performing bronchoscopy developed urticaria within 10 minutes of donning his latex gloves. He recently exhibited symptoms of rhinitis while working in the operating room and night-time cough and wheezing.
- Case 3
A registered nurse, known to have atopic prior to starting her work in nursing, has worked as a scrub nurse in the operating theatre for 4 years. Shortly after a routine cervical smear examination, she developed intense perineal pruritus. While driving home, she became dizzy and developed generalized urticaria.
She presented to the emergency department with hypotension and disorientation, generalized urticaria, flushing and a blood pressure of 70130.
- Case4
A dental hygienist required a laparotomy for colitis. About 50 minutes after the surgical incision the patient developed bronchospasm (with an airway pressure that was so increased that it was necessary to oxygenate and ventilate her), hypotension angioedema and urticaria.
Latex protein hypersensitivity has recently been
implicated as a major public health problem facing
the medical, surgical and medical manufacturing
industry.
Risk Groups and Risk Factors.
Specific groups have been identified to be at high
risk of sensitization to latex protein (Figure 1).
However, latex allergy is not restricted to patients
from these high-risk groups. In a report of life-
threatening anaphylactic reactions related to air contrast barium enemas, most of the patients experiencing
reactions were not from high-risk groups. There
is no accurate prediction of the proportion of the
population that will become sensitized over time.
Figure 1- Groups at High Risk of Developing Latex Allergy
- Spina bifida patients
- Patients with genitourinary tract anomalies
- Healthcare professionals (e.g. dentists, dental hygienists, surgeons, nurses)
- Atopic patients1
- Latex industry workers
- Patients who have undergone multiple surgeries.
1 Patients who are atopic and have frequent exposure to latex gloves may be at highest risk.
Health Care Professionals
- 2.9-16% of health care professionals have been sensitized to latex protein. Female personnel with intense
exposure to latex (e.g., surgeons and theatre nurses) and atopic
individuals are at highest risk. A contact or irritant dermatitis often
precedes the development of immediate hypersensitivity in
health care professionals and others who are sensitized via latex
gloves.
Patients - in the USA, the sensitization rate for patients with spina bifida has ranged from 18-68%.
The risk for atopic patients is approximately 3.8% while the general population seems to be sensitized at a rate of less than
1/1000. All patients undergoing surgery should be asked appropriate
questions (Figure 2). Why patients with spina bifida have a propensity to develop latex allergy is unclear, but is likely to be related to latex exposure, atopic predilection, and multiple surgeries. Patients
with symptomatic sensitization (e.g., rubber contact urticaria, asthma,
anaphylaxis) are at highest risk of developing an anaphylactic reaction
in the operating room.
Figure 2 - Screening Questions for Latex Allergy
- Have you ever experienced a severe allergic reaction or are you aware of an allergic reaction
that occurred during an operation?
- Do you have urticaria or hives after contact with rubber products (e.g. balloons, rubber gloves)?
- Have you had any itching or swelling after contact with condoms?
- Have your tongue or lips ever been swollen or have you had an allergic reaction at the dentist?
- Have you recently developed evidence of asthma or rhinitis or
recurrent sinusitis associated with work? (If patients are healthcare professionals.)
- Questions related to the patient's occupation are helpful indicators of latex allergy risk.
If a medical history consistent with latex allergy is obtained (Figure 3),
elective surgery should be canceled until confirmatory tests can be
performed. It is prudent to assume that all patients
with spina bifida are sensitized to latex. Owing to
the high prevalence of latex allergy in patients with
spina bifida, the usefulness of latex testing in this
group is practically non-existent.
Figure 3 - Manifestations of Allergy Associated with Latex Contact
- Pruntus
- Erytherrla
- Non-urticarial rash
- Urticaria - local (hands) or generalized
- Angioedema
- Rhinoconjunctivitis
- Dyspnea
- Asthma/bronchospasm
- Stridor
- Hypotension
- Anaphylaxix - intraoperative
- Death
IgE-Mediated Hypersensitivity.
Latex contains multiple proteins, lipids, and cis-1,4
polyisoprene, the major component for which it is
harvested commercially to manufacture rubber
products. As latex is a mixed component cytosol,
many residual non-essential components are
retained in the finished rubber product. In addition,
over 100 different chemicals may be used in the
latex manufacturing industry. However, neither the
chemicals nor polyisoprene appear to be the offending antigens in latex immediate hypersensitivity.
IgE-mediated hypersensitivity develops in response
to water-soluble constituent proteins that remain in the latex following the manufacturing process.
Allergenic Proteins
reacting with IgE from sera of
sensitized patients range in size from 14 kD to over
100 kD. With more than 200 proteins of 11 different molecular
weight bands, and several uncharacterized low molecular weight peptides, definitive testing for latex allergy is inconsistent and difficult.
The route of sensitization (e.g., skin, mucosa, intravascular), the
source of protein (i.e., glove or other product), the latex type (e.g.,
low ammoniated, high ammoniated), and individual immune responses may result in variations in the severity of the reaction. For example, a health care professional may react to antigen from only one
glove type and to different antigenic determinants than a patient with
spina bifida.
Diagnosis.
The diagnosis of protein hypersensitivity begins with a relevant history with heightened suspicion if a patient has experienced angioedema, pruritus, urticaria, rhinitis, conjunctivitis or asthma associated with condoms, balloons, rubber gloves or any object containing latex.
If a positive history is obtained, diagnostic testing is the next step.
Latex sensitivity tests - confirmation of latex sensitivity includes:
- skin prick and patch testing for irnmediate wheal and flare response (skin prick is the most sensitive test)
- serological tests for latex-specific IgE
- basophil histamine release
- Iymphocyteproliferation
- flow cytometry
- immunoblot
- provocation tests
- Iatex glove "use" tests.
A patient should be considered sensitized to latex if the history and one confirmatory test are positive.
Care of the Latex-Sensitized Patient in the Operating Theatre
It is necessary to develop a protocol to maintain a latex-free surgical,
and out-patient environment for the sensitized patient (see Figures 1 and 2).
Aerosols - latex protein may be present in the air of the operating theatre as an aerosol and, like pollen, may be inhaled as an aeroallergen. Starch donning powder on gloves absorbs and binds protein
readily and may have a role in making latex antigen airborne.
Low-Allergen Gloves
The use of latex examination and surgical gloves has increased dramatically since the introduction of universal precautions in hospital
and clinic settings. This increased exposure may account for the
emergence of latex allergy as the threshold for sensitization has been
surpassed. The contribution of changes in the allergenicity and processing of latex to increased sensitization has not been established. Thus, use of a glove with a low allergen content may be desirable.
"Hypoallergenic" Gloves - in the USA, the FDA has recommended
that the misleading term "hypoallergenic" should be removed from
gloves. This label was introduced for consumers who developed
either an irritant or contact dermatitis from the accelerator or antioxidant chemicals used in the vulcanizing of rubber gloves. This is a
distinct reaction and is not IgE-mediated. Some patients with immediate hypersensitivity may wrongly assume that these gloves are safe.
One potential problem introduced by this response from the FDA is less quality control in glove manufacturing, because no substitute
labeling has been proposed.
Synthetic gloves - many companies have responded to the allergen problem by manufacturing
synthetic, latex-free gloves (e.g., Dermaprene, Ansell International).
Treatment of Anaphylaxis
Treatment of anaphylaxis includes the use of adrenaline,
oxygen and isotonic fluids. Since anaphylactic reactions may
become biphasic, with recurrence within 8-12 hours, close observation is warranted after a reaction.
Corticosteroids and H, and H2 antagonists are indicated for use with inhaled B-adrenergic agent if the patient has bronchospasm. If a patient is on a B-blocking agent (e.g., propanolol) the response to
standard doses of adrenaline may be incomplete. Higher doses of adrenaline and the use of glucagon may overcome this incomplete response. Confirmation of mast cell degranulation can be confirmed
with a serum tryptase level, which will peak 1-2 hours after the anaphylactic reaction.
Further Reading
- Eghrari-Sabet Js, Slater JE. Latex allergy: a potentially serious respiratory disorder. J. RespirDis 1993; 143: 473-82.
- Kelly KJ, Kurup vP Zacharisen MC, Resnick A, hnk JN Skin and
serologic testing in the diagnosis of latex allergy. J Allergy Clin Immunol 1992; 91: 1140-5.
- Leynadier F, Pecquet c, Dry J. Anaphylaxis to latex during surgery. Anaesthesia 1989; 44: 547-50.
- Ownby D, Tomlanovich M, sammons N, McCullough J. Anaphylaxis associated with latex allergy during barium enema examinations. Am J Roent 1991; 156: 903-8
- Slater J Allergic reactions to natural rubber. Ann Allergy 1992; 68: 203-12.
