1. Latex Allergy: Diagnosis, Prevention, and Management
Tara Hata, MD
Assistant Professor
Dept of Anesthesia, UIHC
March 27, 2001

2. History of Latex Allergy
1933 Contact dermatitis to gloves
1979 Contact urticaria
1982 Identified IgE antibodies to latex proteins
1989 Anaphylaxis and death from latex exposure
Association with spina bifida or severe GU anomalies
1997 Reports to FDA total 2300 allergic reactions (225 anaphylaxis, 53 cardiac arrests, 17 deaths)
1998 FDA mandates labeling of medical products

3. Origin of Latex Latex is sap from rubber tree, Hevea brasiliensis
60% H2O, 35% rubber, 5% protein
Rubber molecule: cis-1,4-polyisoprene
Chemicals added during production
Preservatives (ie: ammonia), accelerators (ie: thiurams), antioxidants (phenylenediamine), vulcanizing compounds (ie: sulfur)
May elicit delayed hypersensitivity
Proteins responsible for most generalized allergies
7 sensitizing proteins identified to date

4. Manufacture of Latex Gloves
Protein content can vary 1000-fold among lots
May vary 3000-fold among manufacturers
Powdered examination gloves have highest protein content and allergen levels
Cornstarch particles adsorb latex allergens
Particles aerosolized: assoc with respiratory symptoms
Particles also contaminate clothing
Lowest levels in powderless gloves that undergo additional washing and chlorination

5. Mechanisms of Exposure
Cutaneous absorption, ie: from gloves
Inhalation via aerosolized proteins on powder
Mucosal
Vaginal/rectal exams, dental procedures, surgery
Parenteral
IVs, surgical wounds, severe dermatitis

6. Hypersensitivity Classification
Type I Immediate
Type II Cytotoxic
Type III Immune complex
Type IV Delayed type

7. Types of Latex Sensitivity
Irritant contact dermatitis
Type IV -- Delayed Hypersensitivity
Type I --Immediate Hypersensitivity

8. Irritant Contact Dermatitis
Most frequent reaction to latex products
Sxs/signs: scaling, drying, cracking of skin
Results from direct action of latex and chemicals
Not a true allergy - no immunologic mechanism
However breakdown in skin integrity enhances absorption of latex proteins
Accelerates onset of sensitivity/allergy
Rx: identify reaction, use alternative product

9. Type IV -- Delayed Hypersensitivity
Synonyms: T-cell mediated contact dermatitis, allergic contact dermatitis
Most common immune response to gloves
Sxs/signs: mild to severe dermatitis (itching, blistering, crusting); appears 6-72 hrs after contact
Cause: processing chemicals in gloves;
mediated by T lymphocytes (not antibodies)
Rx: Identify chemical and use alternative product
Patients may progress to Type I allergy

10. Type I -- Immediate Hypersensitivity
Synonyms: IgE mediated anaphylactic reaction
Cause: proteins in latex
Antigen induces production of IgE; re-exposure to antigen triggers cascade: release of histamine, arachidonic acid, leukotrienes, prostaglandins
Onset within minutes
Varied response: local hives to anaphylactic shock
Rx: Antihistamines, steroids, anaphylaxis protocol
Prevention: avoid latex and areas where powdered gloves used

11. Type I Mediators
Histamine and tryptase release common to type I and IV
Prostaglandins, leukotrienes, eosinophilic chemotactic factor, platelet activating factor
potent bronchoconstrictors, vasodilators
Cytokines released minutes later also cause inflammatory effects

12. Cardiovascular Histamine Receptors
Heart H1 coronary vasoconstriction
H2 coronary vasodilation, tachycardia, inotropy
Arteries H1 vasoconstriction
H1,H2 vasodilation, hypotension
Veins H1 increased permeability, edema
H1, H2 vasodilation, pooling

13. Pulmonary Histamine Receptors
Bronchioles H1 Bronchoconstriction
H2 Mucous secretion
Vasculature H1 Increased permeability

14. Gastrointestinal Histamine Receptors
Smooth muscle H2 Constriction, cramping
Mucosa H2 Acid secretion

15. Cutaneous Histamine Receptors
H1, H2 Vasodilation, increased permeability
Pruritis, urticaria, angioedema

16. Risk Groups for Latex Allergy
Patients with history of multiple surgeries
Meningomyelocele or severe urologic anomalies
Health care workers
Other occupational exposure
Rubber product workers, hair dressers, house cleaners
Individuals with atopy
Hay fever, rhinitis, asthma, or eczema
Patients with specific food allergies
Banana, kiwi, avocado, chestnut, etc.
Similar proteins

17. Myelodysplastic Patients
Prevalence of latex allergy is 18-64%
Type I reactions more common
Predisposing factors
multiple surgeries
daily catheterizations / stoma care
presence of atopy is synergistic factor
Other children at high risk
multiple surgeries starting in neonatal period
those with spinal cord injuries

18. Health Care Workers Typically display a type IV reaction
Can include conjunctivitis, rhinitis, dermatitis
1998 study: prevalence of immediate sensitivity in anesthesiologists & CRNAs 12-16%
Over 80% of those sensitized had no sxs yet
Risk factors: hx atopy, skin sxs with latex gloves, tropical fruit allergies
Progression from type IV to type I unpredictable

19. Diagnosis of Latex Allergy
*Clinical history (ask the right questions)
Myelodysplasia / urologic anomalies
Multiple surgeries
Chronic occupational exposure
Previous reactions to latex products (type I)
Certain food allergies
Atopy
Refer to allergist
Skin testing
In vitro testing

20. Diagnosis by Skin Testing
Diagnose Type IV delayed hypersensitivity
Positive patch test
Reaction appears anytime from 8 hours to 5 days later
Diagnose Type I allergy
Skin prick test using antigens from glove products
Gold standard
Positive test: wheal and flare (c/t + and - controls)
Sensitivity and specificity around 98%
May result in severe reaction

21. Diagnosis by In Vitro Testing
No risk to patient
RAST (radioallergosorbent test)
Measures amount of IgE Ab to latex in serum
Most labs must send out
Takes 5-10 days
Sensitivity 80-90%
Specificity 60-90%
EAST (Enzymeallergosorbent Test)
Does not utilize radioactivity
Sensitivity & specificity of 80-85%

22. Prevention of Reactions in OR
Identify latex sensitive patients
Medic-alert bracelet
Signs on hospital bed, room, and OR
Schedule as 1st start in OR
Use latex free environment
For pts with hx of type I or type IV reactions
Meningomyelocele or urologic anomalies
Post list of latex-containing devices & alternatives
FDA mandated labeling started February 1998
Pretreat pts with positive hx

23. Non-latex Equipment Disposable endotracheal tubes
Esophageal stethoscopes
Oral airways
Suction catheters, Nasogastric tubes
ECG pads
Temp probes
LMAs

24. Potential Latex-Derived Products
Gloves Tape, dressings
Catheters, drains Tourniquets, elastic bandages
IV ports, central lines Medication vials
Syringes Nasal airways, masks, straps
Breathing bag, bellows BP cuff tubing
Stethoscope tubing Oximeter probe
*Check labels!

25. Avoidance of Latex includes:
Avoiding skin contact: BP/stethoscope tubing, IV tourniquets
Remove stoppers from multi-dose med vials
Tape latex injection ports on IV tubing, central lines, IV fluid bags
Use latex free syringes (remember the epidural & spinal trays)

26. Pretreatment Prophylaxis of anaphylaxis is controversial
Efficacy unknown
Anaphylaxis has occurred in pretreated pts
May mask early signs
Pretreat pts with hx of Type I sxs
Start prophylaxis preop and continue x 24 hr
Diphenhydramine 1 mg/kg q 6 hr IV or PO
Methylprednisolone 1 mg/kg q 6 hr IV or PO
Cimetidine 5 mg/kg q 6 hr IV or PO (up to 300 mg)

27. Recognition of Anaphylaxis
Cutaneous
Urticaria
Flushing
Diaphoresis
Perioral / periorbital edema
Conjunctival hyperemia
Lacrimation
Rhinitis

28. Recognition of Anaphylaxis
Respiratory
Laryngeal edema
Bronchospasm
Pulmonary edema
Cardiovascular
Tachycardia, dysrhythmias
Hypotension
CV collapse

29. Management of Anaphylaxis
Remove antigen
100% oxygen
IV volume expansion (up to 50 ml/kg)
D/C or adjust anesthesia
Epinephrine
Bronchospasm or hypotension: ug/kg IV
Cardiac arrest: peds: 10 ug/kg, adults: mg IV
Antihistamine: diphenhydramine 1 mg/kg H2 blocker optional
Steroids: hydrocortisone 1-4 mg/kg

30. Again…... Identify those pts at high risk
For myelodysplastic & GU anomaly pts, as well as those with hx of type I sxs:
Label pt, chart, pt room, OR as latex free
Use latex precautions
Prophylax pts with hx of type I reaction
Be prepared to treat anaphylaxis

31. Conclusion
Most important step is avoidance of exposure in susceptible patients
With universal precautions, the problem will likely worsen
Hospitals should strive for low allergen environments
Powderless gloves with low extractable protein content
Protect yourself
Treat dermatitis
Cover hand wounds with tegaderm