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ALLERGIC REACTIONS
in the
DENTAL OFFICE
Allergic Reactions
Allergy is defined as a hypersensitive state
aquired through exposure to a particular
allergen, reexposure to which produces a
heightened capacity to react
Allergic Reactions
Allergic reactions range from mild, delayed
reactions occuring as long as 48 hours after
exposure, to immediate life-threatening
reactions that occur within seconds after
exposure
Classification of Allergic
Reactions
Type Mechanism Time
I Anaphylactic sec/min
II Cytotoxic
-III Immune
6-8hrs
complex
IV Cell mediated 48 hrs
Example
Angioedema
Transfusion rx
Serum sickness
Contact
dermatitis
Most Common in Dental Office
Type I
Immediate Localized or Generalized
Anaphylaxis - The Type I allergic
reaction is subdivided into several forms
based upon the response
Type IV
Contact Dermatits
Type I
Immediate Hypersensitivity
Generalized (Systemic) Anaphylaxis
Localized Anaphylaxis
Urticaria
Bronchial Asthma
Food Allergy
Antigen
A substance that elicits an allergic
reaction
Antibody
A substance in blood or tissue that responds
and reacts with the antigen
(different in structure than the antigen)
Atopy
Clinical hypersensitivity state, subject to
heredity (asthma, hay fever, etc.)
Urticaria
Wheals (hives)
Smooth elevated patches surrounded by
erythematous areas
Pruritus (itching)
Angioedema
Non-inflammatory edema involving
skin, subcutaneous tissue, underlying muscle
& mucous membranes.
Occurs in response to allergen
Most critical in the larynx
Predisposing Factors in Allergic
Reactions
Prior history of allergy
Genetic predisposition to allergy
- atopic patient
Patient with multiple allergies
Drug that is utilized
Drugs that Cause Allergic
Reactions
Up to 70% of Allergic Reactions
Penicillin
Meprobamate
Codeine
Thiazide Diuretics
Other Substances Causing
Reactions
Iodines
Vaccines
Insulin
Heparin
Salicylates
Sulfonamides
Opiates
Local Anesthetics
Venom from stinging insects
Antibiotic Allergy
Highest incidence
Penicillins (anaphylactic reaction may
prove fatal in 15 minutes)
Sulfonamides
Reactions to erythromycins rarely seen
Analgesic Allergy
Incidence of true allergy to narcotics is low
"Allergy" is most often a side effect such as
nausea, vomiting, drowsiness, dysphoria, or
constipation
Antianxiety Drug Allergy
Barbiturates -most common but occur less
than aspirin and penicillin
Reactions -hives, urticaria, blood dyscrasia
(agranulocytosis / thrombocytopenia)
Allergy occurs more frequently with a history
of asthma, urticaria, and angioedema
Local Anesthetics
Reactions occur most frequently with Esters
Preservatives also cause reactions
Ester Drugs
Procaine
Benzocaine
Related compounds
Procaine Penicillin G
Procainamide
Propoxycaine
Tetracaine
Amide Allergy
The amide type anesthetic are essentially free
of allergic reaction when given in their pure
form
Although true allergy to amide type anesthetic
is extremely rare, patients have
demonstrated allergic reaction to the
contents of the dental cartridge
Ingredient
-
Function
Anesthetic Agent - Conduction blockade
Vasoconstrictor - Decrease absorption
of local anesthetic
Sodium Metabisulfite - Preservative for
vasoconstrictor
Methylparaben - Preservative to increase
shelf life; bacteriostatic
Sodium Chloride - Isotonicity of solution
Sterile Water - Diluent
Paraben Reactions
Preservative found in many non-drug items
Allergic reactions to topical anesthetics
are those of contact stomatitis;
erythema, edema, ulcerations - almost
exclusively a dermatologic type reaction
Clinical Options
Determine type of “allergic” reaction
Substitute different drugs for those which
cause the allergic reaction.
Have patient evaluated by allergist
Management of Allergic
Reactions
Most severe allergic reactions are immediate
A number of organ oystems may be involved
Skin
Cardiovascular
Respiratory
Gastrointestinal
Management of Allergic
Reactions
Generalized anaphylaxis involves all of the
previously mentioned systems
When hypotension occurs, it is termed
Anaphylactic Shock
Affected Area - Manifestation
Skin
Urticaria-Wheal & Flare
pruritis, angioedema, erythema
Respiratory
Dyspnea,wheezing,flushing,
cyanosis,perspiration,tachycardia,
increased anxiety,use of accessory
muscles of respiration
Affected Area - Manifestation
Gastrointestinal
Cardiovascular
Abdominal cramps,
nausea, vomiting, diarrhea,
incontinence
Pallor, light-headedness,
palpitations, tachycardia,
hypotension, dysrhythmias,
loss of consciousness, arrest
Sequence of Reaction
1. Skin reaction
2. Smooth muscle spasm
(GI, GU, and bronchial)
3. Respiratory distress
4. Cardiovascular collapse
Type of Reaction
Quick Onset==> Rapid Progression==>
Intense Reaction
Delayed Onset==> Slow Progression==>
Less Severe Reaction
Drugs Used in Allergic Reactions
Epinephrine
Has Alpha and Beta adrenergic effects
Acts as a physiologic antagonist to the events
that occur during an allergic reaction
Epinephrine
Actions Include
Bronchodilation
Increased heart rate
Arterial constriction
Cutaneous, mucosal, and splanchnic
vasoconstriction
Reverses rhinitis and urticaria
Epinephrine
Risks of repeated use:
Excessive elevation of blood pressure
CVA
Cardiac rhythm abnormalities
Antihistamine
Benadryl (chlorpheniramine) most often used
H-1 blocker
Inhibits action of histamine released during
reaction to allergen
Corticosteroids
Hydrocortisone used most often
Stablilizes cell membranes against actions of
histamines, bradykinins, and prostaglandins
Supplements adrenal steroid output during
stress
Treatment of
Immediate Skin Reactions
Epinephrine 0.3 mg IM or SC
(0.3ml of a 1:1000 Solution)
Antihistamine
Diphenhydramine (Benadryl) 50 mg IM
Treatment of
Immediate Skin Reactions
Obtain medical consultation
Observe patient for at least one hour
Prescribe oral antihistamines
Benadryl 50 mg PO Q6H for 3-4 days
Treatment of
Delayed Skin Reactions
Antihistamine
Diphenhydramine (Benadryl) 50 mg IM
Prescribe oral form Q6H for 3-4 days
Arrange medical consultation
Treatment of
Respiratory Reactions
Bronchial Constriction
Terminate dental treatment
Sit patient upright
Oxygen 6 L/min
Epinephrine aerosol or 0.3 mg IM or SC
(0.3 ml of a 1:1000 solution)
Treatment of
Respiratory Reactions
Bronchial Constriction (cont.)
Observe for at least 1 hr
Antihistamines - Benadryl 50 mg IM
Obtain medical consulatation
Prescribe oral antihistamines
(Q6H for 3-4 days)
Treatment of
Respiratory Reactions
Laryngeal Edema
Sit patient upright
Epinephrine 0.3 mg IM or IV
Maintain airway
Summon medical assistance
Treatment of
Respiratory Reactions
Laryngeal Edema (cont.)
Oxygen 6 L/min
Cricothyroidotomy
Additional drug therapy
Diphenhydramine 50mg
&/or
Hydrocortisone 100 mg
Generalized Anaphylaxis
with Signs of Allergy
Place patient in a supine postion
Basic Life Support (ABCs)
Administer epinephrine 0.3 mg IM or SC
(0.3 ml of a 1:1000 solution)
Summon medical assistance - call 911
Generalized Anaphylaxis
with Signs of Allergy
Monitor vital signs
Additional drug therapy
Antihistamines
Corticosteroids
Repeat epinephrine Q5min prn
Generalized Anaphylaxis
without Signs of Allergy
Place patient in a supine position
Basic Life Support
Monitor vital signs
Summon medical assistance prn
Generalized Anaphylaxis
without Signs of Allergy
Consider possible causes of unconsciousness
Syncope
Overdose Reaction
Hypoglycemia
CVA
Acute Adrenal Insufficiency
Prevention of Allergic Reactions
HISTORY - a thorough, complete history of
any previous allergic response or tendency
prior to starting treatment will avoid most
emergencies
Other Means of Prevention
Medical consultation
Dental office skin testing
(not foolproof and not advisable)
Take Home Lessons
All positive responses to an allergy history are
true until exact nature is determined!
Patients reporting allergies should be critically
evaluated -refer for allergy testing if history,
reaction, or management are suspect.
Be prepared to manage difficulties! Always!