Latex Allergy Diagnosis Prevention and Management

Latex Allergy: Diagnosis, Prevention, and Management Tara Hata, MD Assistant Professor Dept of Anesthesia, UIHC March 27, 2001 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 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 (ie: ammonia), accelerators (ie: thiurams), antioxidants (phenylenediamine), vulcanizing compounds (ie: sulfur)  May elicit delayed hypersensitivity  Preservatives  Proteins responsible for most generalized allergies 7 sensitizing proteins identified to date 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 particles adsorb latex allergens  Particles aerosolized: assoc with respiratory symptoms  Particles also contaminate clothing  Cornstarch  Lowest levels in powderless gloves that undergo additional washing and chlorination 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 Hypersensitivity Classification     Type I Type II Type III Type IV Immediate Cytotoxic Immune complex Delayed type Types of Latex Sensitivity    Irritant contact dermatitis Type IV -- Delayed Hypersensitivity Type I --Immediate Hypersensitivity 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 breakdown in skin integrity enhances absorption of latex proteins  Accelerates onset of sensitivity/allergy  However  Rx: identify reaction, use alternative product 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 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 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 Cardiovascular Histamine Receptors Heart H1 H2 H1 H1,H2 H1 H1, H2 Arteries Veins coronary vasoconstriction coronary vasodilation, tachycardia, inotropy vasoconstriction vasodilation, hypotension increased permeability, edema vasodilation, pooling Pulmonary Histamine Receptors Bronchioles H1 H2 H1 Bronchoconstriction Mucous secretion Increased permeability Vasculature Gastrointestinal Histamine Receptors Smooth muscle Mucosa H2 H2 Constriction, cramping Acid secretion Cutaneous Histamine Receptors H1, H2 Vasodilation, increased permeability Pruritis, urticaria, angioedema 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 Myelodysplastic Patients    Prevalence of latex allergy is 18-64% Type I reactions more common Predisposing factors surgeries  daily catheterizations / stoma care  presence of atopy is synergistic factor  multiple  Other children at high risk  multiple surgeries starting in neonatal period  those with spinal cord injuries 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% 80% of those sensitized had no sxs yet  Risk factors: hx atopy, skin sxs with latex gloves, tropical fruit allergies  Over  Progression from type IV to type I unpredictable 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 Diagnosis by Skin Testing  Diagnose Type IV delayed hypersensitivity patch test  Reaction appears anytime from 8 hours to 5 days later  Positive  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 Diagnosis by In Vitro Testing   No risk to patient RAST (radioallergosorbent test) amount of IgE Ab to latex in serum  Most labs must send out  Takes 5-10 days  Sensitivity 80-90%  Specificity 60-90%  Measures  EAST (Enzymeallergosorbent Test)  Does not utilize radioactivity  Sensitivity & specificity of 80-85% 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 Non-latex Equipment        Disposable endotracheal tubes Esophageal stethoscopes Oral airways Suction catheters, Nasogastric tubes ECG pads Temp probes LMAs Potential Latex-Derived Products Gloves Catheters, drains IV ports, central lines Syringes Breathing bag, bellows Stethoscope tubing Tape, dressings Tourniquets, elastic bandages Medication vials Nasal airways, masks, straps BP cuff tubing Oximeter probe *Check labels! 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) 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) Recognition of Anaphylaxis  Cutaneous  Urticaria  Flushing  Diaphoresis  Perioral / periorbital edema  Conjunctival hyperemia  Lacrimation  Rhinitis Recognition of Anaphylaxis  Respiratory edema  Bronchospasm  Pulmonary edema  Laryngeal  Cardiovascular  Tachycardia,  Hypotension  CV dysrhythmias collapse Management of Anaphylaxis      Remove antigen 100% oxygen IV volume expansion (up to 50 ml/kg) D/C or adjust anesthesia Epinephrine or hypotension: 0.1-5 ug/kg IV  Cardiac arrest: peds: 10 ug/kg, adults: 0.5-2 mg IV  Bronchospasm   Antihistamine: diphenhydramine 1 mg/kg H2 blocker optional Steroids: hydrocortisone 1-4 mg/kg 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 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 dermatitis  Cover hand wounds with tegaderm  Treat