Ahmad H. Bani-Hani, MD, FAAP, FACS
BASICS
DESCRIPTION
• Localized or systemic reaction to latex, a natural substance from the sap of the rubber tree, Hevea brasiliensis (1)[A].
• Latex is a common ingredient in many medical and dental products (eg, bladder catheters, blood pressure cuffs, face mask, gloves, endotracheal tubes, IV infusion sets, etc.)
• Patients with spina bifida or congenital urogenital abnormalities have the highest risk.
• Mild forms include pruritus and swelling. The most severe form of allergic reaction is anaphylaxis: A severe, life-threatening, generalized or systemic hypersensitivity reaction characterized by rapidly developing life-threatening airway and/or breathing and/or circulation problems usually associated with skin and mucosal changes.
ALERT
All patients with neurogenic bladder should be considered for latex precautions.
EPIDEMIOLOGY
Incidence
• Latex sensitivity (assessed by serum latex IgE or skin prick test) in the general population is <1%
– Spina bifida population is 18–72%
• Latex allergy (eg, anaphylactic symptoms) is rare in healthy population.
• Healthcare community: Up to 12.1% which fell to 4% with the introduction of powder-free gloves
• Exposure to multiple surgeries: 1/3–2/3 of children who underwent surgeries in the 1990s developed latex sensitivity; this risk decreased dramatically since the implementation of latex avoidance in hospitals and products
Prevalence
N/A
RISK FACTORS
• Occupational exposure:
– Healthcare
– Food handlers/restaurant workers
– Hairdressers
– Construction workers
– Painters
– First responders
– Security personal
– Gardeners
• Atopic disease
• People with food allergies mainly to kiwi, strawberry, banana, avocado, chestnut
• Multiple surgeries at young age
• Children with anorectal or urologic malformations (5)[A].
– Spinal dysraphism
– Bladder exstrophy/cloacal anomalies
– Patients on clean intermittent catheterization
Genetics
• Genetic factor might be indicated.
• Latex allergy is less frequent in adults with spinal cord injury and multiple surgical procedures than in children with similar conditions.
• Interleukin-13 (IL-13) and IL-18 promoter polymorphisms more likely to be found in healthcare workers in comparison to nonatopic controls or patients with anorectal/urologic malformations.
PATHOPHYSIOLOGY
• Presensitization with Hevea latex allergens is prerequisite to initiate an allergic response.
• A number of proteins found in the cytoplasm of H. brasiliensis are known potent allergens that can elicit human IgE antibody, leading to sensitization in exposed patients and a spectrum of allergic reactions upon subsequent exposure (4)[A].
• Symptoms of delayed (type IV) hypersensitivity usually develop within 1–2 days of exposure. Immediate (type I) hypersensitivity causes symptoms within minutes of exposure.
• Immediate hypersensitivity reactions to latex (type I) are caused by cross-linking of latex protein-specific IgE antibody with mast cells and basophils.
• Cross-reactivity between various proteins is responsible for the clinical associations between latex allergy and allergic responses to a number of fruits and vegetables.
• Type IVc (T-cell–mediated type), delayed hypersensitivity reaction can occur and usually manifest as contact dermatitis 24–96 hr after exposure.
GENERAL PREVENTION
• Facility:
– Avoidance is the most effective and least expensive method.
– Establishment of a latex-safe environment should be a priority for institutions by replacing all Hevea latex–containing products with non–Hevea-based synthetic products or powder-free latex products.
– Synthetic alternatives to rubber include butyl rubber, a petroleum-based product with no allergenic protein, neoprene, and copolymers of butadiene and acrylonitrile.
– Non-Hevea source of natural rubber is the guayule plant (Yulex). Yulex-based products pose no risk to individuals allergic to Hevea latex and is approved by the Food and Drug Administration (FDA).
• Individuals with latex allergy:
– Should wear a medical alert bracelet indicating latex allergy
– Should be encouraged to have self-injectable epinephrine if they have a clinical history of systemic reaction to latex
– Should avoid latex-containing products
– Should report their allergies prior to any medical or surgical procedure
DIAGNOSIS
HISTORY
• Detailed clinical history of allergic reactions that are temporarily associated with exposure to Hevea latex–containing products (eg, prior history to anaphylaxis and/or intraoperative shock, itching, redness, or swelling following dental, rectal, or pelvic exam; itching or swelling with condoms, diaphragms, or latex sexual aids)
• Detailed history of associated risk factors: Healthcare workers, hair dressers, rubber handling, eczema/hay fever, multiple surgeries, food allergies, etc.
• 30–80% of patients with latex allergy also have food allergy
• Allergic symptoms can include the following symptoms:
– Dizziness
– Dyspnea
– Pruritus
– Rhinitis
– Tearing
– Swelling at the site of contact
– Abdominal cramps
• In the most extreme cases, anaphylaxis can develop
ALERT
Use caution when examining any child for dysfunctional voiding especially if the child has neurologic symptoms or suspected spina bifida.
PHYSICAL EXAM
• Use nonlatex exam gloves
– Mucocutaneous manifestations:
Erythema
Edema
Papules, macules, urticaria
Allergic rhinitis
Allergic conjunctivitis
Angioedema
– Cardiopulmonary manifestations:
Tachypnea
Stridor, wheezing
Tachycardia
Hypotension
Shock
DIAGNOSTIC TESTS & INTERPRETATION
Lab
Routine resuscitation lab studies (blood gas, etc.) if during acute anaphylaxis
Imaging
N/A
Diagnostic Procedures/Surgery
• These are performed on a routine basis and not during an acute event
• Prick skin test:
– Extracts of Hevea latex, at least 3
– Commercial extracts are available
– Test involves performing a puncture with a lancet device through a drop of latex extract at sequential concentrations ranging from 0.001–1 mg/mL of protein
– Results are read after 15 min and compared with the positive histamine and negative saline controls
– Small risk of anaphylaxis
• Serology:
– An alternative test for confirming sensitization when commercial skin test reagents are not available
– Involves measuring serum Hevea latex–specific IgE antibodies
– Diagnostic sensitivity and specificity: 80% and >95%, respectively
Pathologic Findings
• Biopsy of skin lesions (type IV hypersensitivity):
– Perivascular cuffing of CD4 cells identified using anti-CD4 antibody staining
– Vesicular dermatitis with dermal and epidermal mononuclear infiltrates
DIFFERENTIAL DIAGNOSIS
• Systemic allergic reaction to another allergen, including medications or food products.
• Mild allergic manifestations:
– Allergic rhinitis
– Asthma
– Atopic dermatitis (ie, eczema)
– Conjunctivitis
– Contact dermatitis to other allergens (ie, nickel products)
• Severe life-threatening manifestations:
– Anaphylactic shock
– Cardiogenic shock
– Septic shock
– Hypovolemic shock
TREATMENT
GENERAL MEASURES
• Latex avoidance is by far the most-effective method of prevention (2,3)[A].
• Institutional policy changes in the use of Hevea products are needed to reduce occupational and patient exposure.
• Always seek the use of nonlatex alternative products (eg, silicone urethral catheters)
• Synthetic and Yulex, non-Hevea rubber, are safe alternatives in Hevea-sensitized individuals.
• Additional measures recommended for patients with latex allergy include carrying nonlatex gloves, wearing medical alert bracelets, and having auto-injectable epinephrine available.
• For acute anaphylaxis, standard shock management.
MEDICATION
First Line
• For the management of anaphylaxis
– Remove latex source
– Basic life support principles (Airway, Circulation, Breathing)
– Injectable epinephrine in severe anaphylaxis
0.3–0.5 mL of a 1:1000 solution IM (adult)
0.15–0.3 mL of a 1:000 solution IM (children)
– Epinephrine autoinjectors:
EpiPen, Adrenaclick (0.3 mg) in adults
EpiPen Jr., Adrenaclick (0.15 mg) in children
• Supportive medications cannot be substituted for epinephrine in the emergent management of anaphylaxis because they do not prevent or relieve respiratory failure or shock, but can be useful after initial resuscitation
– Antihistamines (diphenhydramine)
– Bronchodilators (albuterol)
– Steroids (hydrocortisone)
– H2 blockers (ranitidine)
Second Line
N/A
SURGERY/OTHER PROCEDURES
N/A
ADDITIONAL TREATMENT
Radiation Therapy
N/A
Additional Therapies
N/A
Complementary & Alternative Therapies
• Most healthcare facilities have banned latex helium–filled balloons and are striving to become latex-free.
• There is no desensitization available, but several including sublingual and other immunotherapies are under study.
ONGOING CARE
PROGNOSIS
• Depends on severity of symptoms and timely identification of responsible agents.
• High index of suspicion and immediate treatment are essential to good outcome.
• Individuals with severe latex allergy should be provided with epinephrine autoinjections.
• Patients with type I hypersensitivity: Risk of fatal anaphylaxis and/or respiratory compromise
COMPLICATIONS
• Death can result from anaphylactic shock
• Secondary bacterial wound infections in cases of severe contact dermatitis
FOLLOW-UP
Patient Monitoring
• Some patients experience a biphasic or late stage reaction several hours after the initial anaphylactic event. Patients should be observed for at least 4 hr after the initial event.
• Avoidance should extend outside of the hospital to items such as latex balloons, rubber bands, toys, etc.
• Inpatient admission may be necessary until cardiopulmonary risk is reduced.
• Allergy identification band, “MedicAlert" bracelet
• Avoid foods with latex cross-reactivity:
– Banana, kiwi, chestnut, avocado
Patient Resources
• http://www.latexallergyresources.org/
• http://www.aaaai.org/conditions-and-treatments/allergies/latex-allergy.aspx
• http://www.nlm.nih.gov/medlineplus/latexallergy.html
REFERENCES
1. Bernstein DI. Management of natural rubber latex allergy. J Allergy Clin Immunol. 2002;110:S111–S116.
2. Blumchen K, Bayer P, Buck D, et al. Effects of latex avoidance on latex sensitization, atopy and allergic diseases in patients with spina bifida. Allergy. 2010;65:1585–1593.
3. Cusik C. A latex-safe environment is in everyone’s best interest. Mater Manag Health Care. 2007;16:24–26.
4. Accetta D, Kelly KJ. Recognition and management of the latex-allergic patient in the ambulatory plastic surgerical suite. Aesthet Surg J. 2011;31:560–565.
5. Brown RH, Hamilton RG, McAllister MA; Johns Hopkins Latex Task Force. How health care organizations can establish and conduct a program for latex-safe environment. Jt Comm J Qual Saf. 2003;29:113–123.
ADDITIONAL READING
• Bernardini R, Novembre E, Lombardi E, et al. Prevalence of and risk factors for latex sensitization in patients with spina bifida. J Urol. 1998;160:1775–1778.
• Reddy S. Latex allergy. Am Fam Physician. 1998;57(1):93–100.
See Also (Topic, Algorithm, Media)
Myelodysplasia (Spinal Dysraphism), Urologic Considerations
CODES
ICD9
• 596.54 Neurogenic bladder NOS
• 753.9 Unspecified anomaly of urinary system
• V15.07 Allergy to latex
ICD10
• N31.9 Neuromuscular dysfunction of bladder, unspecified
• Q64.9 Congenital malformation of urinary system, unspecified
• Z91.040 Latex allergy status
CLINICAL/SURGICAL PEARLS
• Natural rubber latex allergy is caused by sensitization to proteins found in H. brasiliensis, the rubber tree.
• The highest prevalence of latex allergy (up to 68%) is in patients with spina bifida or congenital urogenital abnormalities.
• The mainstay of management of latex allergy is avoidance of latex products as there is no cure for latex allergy.