Chapter 19 Allergy

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Chapter 19
Allergy
Modified by: Megan Simpson

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Allergy
 Allergic disorders are increasing in
prevalence and contributing significantly to
health care costs
 One of the most common medical emergencies that
can occur in the dental office is that of an acute
allergic reaction
 A requirement of every dental practitioner is a basic
understanding of the pathophysiology of such
reactions, as well as risk factors and clinical
manifestations

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Allergy (cont’d)
 Such knowledge will permit meeting the goals of
safe and effective dental treatment
 To identify patients with a true allergic history, so acute
medical emergencies potentially occurring in the dental
office because of an allergic reaction can be prevented
 To recognize head, neck, and oral tissue changes that
might be caused by an allergic reaction
 To identify and plan appropriate dental care for patients
who have severe alterations of the immune system
secondary to irradiation or drug therapy or related to an
immune deficiency disorder
 To recognize signs and symptoms of acute allergic
reactions and to manage these problems appropriately

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Epidemiology
 Allergy is an abnormal or hypersensitive
response of the immune system to a
substance introduced into the body
 It is estimated that more than 25% of all Americans
demonstrate an allergy to some substance, including
10 to 20% who have allergic rhinoconjunctivitis, 7%
who have a diagnosed food allergy, 7% who have
asthma, 4% who are allergic to insect stings, and
5% who are allergic to one or more drugs

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Epidemiology (cont’d)
 About a 1% to 3% risk for an allergic reaction
is associated with administration of any drug
 Drugs are the most common cause of
urticarial reactions in adults, and food and
infection are the most common causes of
these lesions in children
 Urticaria occurs in 15% to 20% of young adults
 In approximately 70% of patients with chronic
urticaria, no etiologic agent can be identified

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 Anaphylaxis in dental practice is estimated to
occur in 0.004 to 0.015 cases per dentist per
year
 About 10% of people who take penicillin develop an
allergic reaction and 0.04% to 0.2% of these
experience anaphylaxis
 Death occurs in about 1% to 10% of those persons
who experience an anaphylactic reaction
 Usually, in anaphylactic reactions to penicillin, death
occurs within 15 minutes after drug administration

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 In rare cases, antihistamines have been
reported to cause urticaria through an allergic
response to the colored coating material of
the capsule
 In addition, azo and nonazo dyes used in toothpaste
have been reported to cause anaphylactic-like
reactions
 Aniline dyes used to coat certain steroid tablets have
caused serious allergic reactions as well

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 Parabens (used as preservatives in local
anesthetics) have caused anaphylactoid
reactions
 Sulfites (sodium metabisulfite or acetone sodium
bisulfite) used in local anesthetic solutions to prevent
oxidation of the vasoconstrictors can cause serious
allergic reactions
 The group most susceptible to allergic reactions caused
by sulfites includes the 9 to 11 million persons in the U.S.
in whom asthma has been diagnosed
 Allergy to latex occurs in between 1% and 6% of the
general population, and much more commonly in persons
who have spina bifida

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Etiology
 Foreign substances that trigger hypersensitivity
reactions are called allergens or antigens
 Two types of lymphocytes play central roles in the two
branches of the specific immune system
 B lymphocytes in the humoral branch
 T lymphocytes in the cellular branch

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Pathophysiology and Complications
 Humoral immune system
 B lymphocytes recognize specific foreign chemical
configurations via receptors on their cell membranes
 For the antigen to be recognized by specific
B lymphocytes, it must first be processed by
T lymphocytes and macrophages
 Once recognition has taken place, B lymphocytes
differentiate and multiply, forming plasma cells and
memory B lymphocytes

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Humoral Immune System
 Memory B lymphocytes remain inactive until
contact is made with the same type of antigen
 This contact transforms the memory cell into a
plasma cell that produces immunoglobulins
(antibodies) specific for the antigen involved
 There are five classes of immunoglobulins
 Immunoglobulin E is the key antibody involved in the
pathogenesis of type I hypersensitivity reactions

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Humoral Immune System (cont’d)
 Type I, type II, and type III hypersensitivity
reactions involve elements of the humoral
immune system
 Type I sensitivity is an IgE-mediated reaction that
leads to the release of chemical mediators from
mast cells and basophils in various target tissues
 The role of IgE is clear in such reactions, but that of
the other sensitizing antibody, IgG, is not well
understood

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Type I Hypersensitivity
 Type I hypersensitivity reactions commonly
are caused by food substances, antibiotics,
and insect bites
 They are related to the humoral immune system and
usually occur soon after second contact with an
antigen (however, many people have repeated
contacts with a specific drug or material before they
become allergic to it)

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Type I Hypersensitivity (cont’d)
 Anaphylaxis is an acute reaction involving the
smooth muscle of the bronchi in which
antigen–IgE antibody complexes form on the
surface of mast cells, which causes sudden
histamine release from these cells
 Release of histamine, as well as other vasoactive
mediators, leads to smooth muscle contraction and
increased vascular permeability
 The potential end result is acute respiratory
compromise and cardiovascular collapse

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 Atopy is a hypersensitivity state that is
influenced by hereditary factors
 Hay fever, asthma, urticaria, and angioedema are
examples of atopic reactions
 Lesions most commonly associated with atopic
reactions include urticaria, which is a superficial
lesion of the skin, and angioedema, which is a lesion
that occurs in the deep dermis or subcutaneous
tissue and often involves diffuse enlargement of the
lips, infraorbital tissues, larynx, or tongue

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 There are many types of angioedema
 Three types of interest to dentistry are acquired (allergic-
based), drug-induced, and hereditary angioedema
 Drug-induced angioedema results from impaired
bradykinin degradation after administration of certain
drugs, such as angiotensin-converting enzyme inhibitors
 The hereditary form is due to a deficiency or dysfunction
of complement C1 inhibitor, which can be triggered by
trauma, thus leading to activation of the complement
cascade and Hageman factor (factor XII) and
overproduction of bradykinin

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Type II Hypersensitivity
 These reactions are IgG- or IgM-mediated
reactions that result in destruction of the
targeted cells by complement and antibodies
 The classic example of type II (cytotoxic)
hypersensitivity is transfusion reaction caused by
mismatched blood

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Type III Hypersensitivity
 These reactions occur when there is excess
antigen in the bloodstream
 The antigen-antibody complexes migrate under the
membrane of small blood vessels, which sets off the
complement cascade
 This leads to an inflammatory response with key
features of vasculitis, swelling and pain
 Clinical examples include systemic lupus
erythematosus and streptococcal glomerulonephritis

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Cellular Immune System
 In the cellular or delayed immune system,
T lymphocytes play the central role
 The primary function of this system is to recognize
and eradicate antigens that are fixed in tissue or
within cells
 This system is involved in protection against viruses,
tuberculosis, and leprosy
 Antibodies are not operative in the cell-mediated
immune system
 Effector T lymphocytes produce various cytokines
that serve as active agents of this system

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Type IV Hypersensitivity
 Type IV hypersensitivity, involving the cellular
immune system, include infectious contact
dermatitis, transplant rejection, graft-versus-host
disease
 Events in type IV hypersensitivity, which may involve
dendritic cells and Langerhans cells, present the antigen to
undifferentiated T lymphocytes
 Some of the more common antigens that cause contact
dermatitis include metal jewelry, perfumes, rubber products,
chemicals such as formaldehyde, and medicines such as
topical anesthetics
 Reactions usually appear 2-3 days after allergen contact

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Type IV Hypersensitivity (cont’d)
 Infectious-type allergic reactions are
exemplified by the tuberculin skin test
 A person who has previously been exposed to
Mycobacterium tuberculosis develops, after a
second exposure in the form of an intradermal
injection of altered bacteria, a delayed response—
usually within 48 to 72 hours

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Type IV Hypersensitivity Reactions
(cont’d)
 Graft rejection occurs when organs or tissues
from one body are transplanted into another
 Cellular rejection of transplanted tissue occurs unless the
donor and recipient are genetically identical or the host
immune response has been suppressed
 Graft-versus-host reaction is an unusual phenomenon
that occurs in bone marrow transplant recipients whose
cellular immune system has been rendered deficient by
whole body irradiation
 Lymphocytes transferred to the host try to attack tissues

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Nonallergic Reactions/
Pseudoallergy
 Other agents may cause mast cells to release
their mediators without inciting a true allergic
reaction
 This occurs in cases of chronic urticaria caused by
certain drugs, temperature changes, and emotional
states, and in some reactions to drugs
 Most so-called anaphylactic reactions to local anesthetics
do not involve an antigen-antibody reaction but result
from damage to the mast cells caused by other
mechanisms
 These reactions are referred to as anaphylactoid or
anaphylaxis-like

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Nonallergic Reactions/
Pseudoallergy (cont’d)
 From the clinical standpoint, approaches to
management of anaphylactic and
anaphylactoid reactions are similar
 These types of drug reactions are viewed as true
allergic reactions
 Nonallergic cases of urticaria, angioedema, and
anaphylactoid reactions are caused by the
nonspecific release of vasoactive amines from mast
cells or by the activation of other forms of
nonspecific immunologic effectors involving the
complement system and Hageman factor–
dependent pathway

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Laboratory and
Diagnostic Findings
 Patients with IgE mediated allergy can have
elevated levels of total IgE, allergen-specific
IgE and eosinophils in their serum or nasal
passages, and will test positive to a specific
allergen following skin testing
 Tryptase blood tests are helpful in diagnosing
anaphylaxis

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Medical Management
 Patients with atopy may be given injections to
gradually desensitize them so that they are no
longer allergic to the antigen
 Some patients with severe asthma may be forced to
move to an area of the country that does not contain the
antigen
 Patients with asthma, immune complex injury, or
cytotoxic immune reactions may be treated with
systemic steroids
 Those with hay fever or urticaria are treated with
antihistamines

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Medical Management (cont’d)
 Newer antihistamines are highly effective and
produce fewer side effects (e.g., drowsiness)
 These agents differ in a number of ways (tablet size,
duration of effect, efficacy, triggering sleepiness, adverse
effects, drug interactions, price)
 A variety of treatments have been used for patients with
contact dermatitis
 From a dental standpoint, the patient being treated for
allergies has an increased chance of being allergic to
another substance
 In a person taking steroids, the body’s reaction to stress
may be impaired

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Dental Management
 Identification and Risk Assessment
 One of the most common concerns is patient-
reported allergy to a local anesthetic,
antibiotic, or analgesic
 The history then must be expanded, with specific
efforts made to determine exactly what the offending
substance was and exactly how the patient reacted
to it

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Identification and
Risk Assessment
 If the adverse reaction was of an allergic
nature, one or more of the classic signs or
symptoms of allergy should have been
present
 If these signs or symptoms were not reported, the
patient probably did not experience a true allergic
reaction
 Common examples of reactions mislabeled as
“allergy” are syncope after injection of a local
anesthetic and nausea or vomiting after injection of
codeine

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Anesthetics
 A common reaction to local anesthetics
involves an anxious patient who, because of
concern about receiving a “shot,” experiences
a psychogenic reaction that includes
hyperventilation, tachycardia, sweating,
paleness, and syncope
 Local anesthetics containing a vasoconstrictor can
cause an epinephrine reaction (tachycardia,
sweating, paleness), which usually results from
inadvertent intravenous injection

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Anesthetics (cont’d)
 If the patient’s history supports a toxic or
vasoconstrictor reaction
 The dentist should explain the nature of the previous
reaction and should avoid injecting the local
anesthetic solution intravenously by aspirating
before the injection and limiting the amount of
solution to the recommended dose
 If the patient’s history supports an
interpretation of fainting and not a toxic or
allergic reaction
 The dentist’s primary task will be to work with the
patient to reduce anxiety during dental visits

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 If the history supports a true allergic reaction
to the local anesthetic
 The dentist should try to identify the type of local
anesthetic that was used
 Once this has been ascertained, a new anesthetic
with a different basic chemical structure can be used

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 The two main groups of local anesthetics in
dentistry consist of
 Para-aminobenzoic acid (PABA) esters
 Amides
 Benzoic acid ester anesthetics may cross-
react with each other, whereas amide
anesthetics usually do not cross-react
 Cross-reaction does not occur between ester and
amide local anesthetics

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 Procaine is the local anesthetic associated
with the highest incidence of allergic
reactions
 Currently, it is available only in multidose vials
 Its antigenic component appears to be PABA, one of
the metabolic breakdown products of procaine

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 Cross-reactivity has been reported between
lidocaine and procaine (however, this
potentially was due to the presence of a
germicide, methylparaben, which previously
was used in small amounts as a preservative
and is chemically similar to PABA)
 Methylparaben is no longer used as a preservative,
so this problem is no longer a concern

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 Patients who have been allergic to local
anesthetics but who cannot identify the
specific agent to which they have reacted
present more of a diagnostic problem
 If the reaction is consistent with an allergic reaction,
the next step should be to attempt to identify the
anesthetic used
 When the patient is unable to provide this
information, the dentist can attempt to contact the
previous dentist involved

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 If this fails, two additional options are
available
 An antihistamine (e.g., diphenhydramine [Benadryl])
can be used as the local anesthetic
 The patient may be referred to an allergist for
provocative drug testing (PDT)

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 A 1% solution of diphenhydramine that contains
1:100,000 epinephrine can be easily
compounded by a pharmacist, but it must be
confirmed that methylparaben is not used as a
preservative
 This solution induces anesthesia of about 30 minutes
average duration and can be used for infiltration or block
injection
 When it is used for a mandibular block, 1 to 4 mL of
solution is needed
 No more than 50 mg of diphenhydramine should be given
during a single appointment

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 The dentist may elect to refer the patient to
an allergist for evaluation and testing, which
usually includes both skin testing and PDT
 Most investigators agree that skin testing alone for
allergy to local anesthetic is of little benefit because
false-positive results are common (therefore, the
allergist also should perform PDT)

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 The allergist selects a local anesthetic for testing
that is least likely to cause an allergic reaction
(usually an anesthetic from the amide group that
does not cross-react with each other)
 At 15-minute intervals, 0.1 mL of test solution is injected,
with concentrations increasing from 1:10,000 to 1:1,000
to 1:100 to 1:10, followed by undiluted solution; then, 0.5
mL of undiluted test solution is tried; and finally, 1 mL of
undiluted solution is given
 Under these conditions, a local anesthetic that causes no
reaction can be used in the tested patient, and the risk of
an allergic reaction is no greater than in the general
population

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 When administering an alternative anesthetic
to a patient with a history of a local anesthetic
allergy
 Inject slowly, aspirating first to make sure that a
vessel is not being injected
 Place 1 drop of the solution into the tissues
 Withdraw the needle and wait 5 minutes to see what
reaction, if any, occurs. If no allergic reaction occurs,
as much anesthetic as is needed for the procedure
should be deposited. (Be sure to aspirate before
giving the second injection.)

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Penicillin
 Penicillin is used frequently throughout the
world and is a common cause of drug allergy
 In the U.S., about 5% to 10% of the population is
allergic to penicillin and penicillin-related drugs
 About 0.04% to 0.2% of patients treated with
penicillin develop an anaphylactic reaction
 This is fatal in about 10% of these patients,
accounting for some 400 to 800 deaths per year

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Penicillin (cont’d)
 The possibility of sensitizing a patient to
penicillin varies with different routes of
administration
 Oral administration results in sensitization of only
about 0.1% of patients, intramuscular injection in
about 1% to 2%, and topical application in about 5%
to 12%
 On the basis of these data, the use of penicillin in a
topical ointment is contraindicated
 If the dentist has a choice, the oral route is
preferable for administration whenever possible

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 Parenteral administration of penicillin evokes
a more serious reaction than that typically
associated with oral administration
 Some investigators have suggested that the risk of
serious allergic reaction is great with both routes
 Antibodies produced against penicillin cross-react
with the semi-synthetic penicillins and may cause
severe reactions in patients who are allergic to
penicillin
 Synthetic penicillins seem to cause fewer new
sensitizations in patients not allergic to it at the time
of administration

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 Skin testing for allergy to penicillin is much more
reliable than is skin testing for allergy to a local
anesthetic
 To be cost-effective, the test should be conducted only on
patients with a history of penicillin reaction who
nevertheless need penicillin for a serious infection
 Penicillin reactivity declines with time (hence, a patient
may have reacted to the drug years ago but is now no
longer sensitive
 Most anaphylactic reactions to penicillin occur in patients
who have been treated in the past with penicillin but
reported no adverse reactions

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 When skin testing for penicillin sensitivity is
performed, both metabolic breakdown products
of penicillin (the major derivative, penicilloyl
polylysine, and the minor derivative mixture)
must be tested
 95% of penicillin is metabolized to the major determinant,
and 5%, to the minor determinants
 If skin test results are negative for both breakdown
products, the patient is considered not allergic to
penicillin
 If positive skin test results are obtained for one or both of
the breakdown products, the patient is considered to be
allergic to penicillin, and the drug not used

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 In dentistry, a patient who self-reports allergy
to penicillin should be carefully interviewed to
determine the plausibility of the allergy
 If the information provided is convincing, then the
patient is generally best treated with an alternative
antibiotic
 For example, patients with a history of penicillin
allergy should be given erythromycin or clindamycin
for the treatment of oral infection or clindamycin for
prophylaxis against infective endocarditis

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 Cephalosporins are often used as alternatives to
penicillins (however, cephalosporins cross-react
in 5% to 10% of penicillin-sensitive patients)
 Cephalosporins usually can be used in patients with a
history of distant, nonserious reaction to penicillin
 However, skin testing is recommended for these patients
by some investigators
 If the penicillin skin test result is positive, a skin test for
the specific cephalosporin selected should be performed

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 Patients with a negative history of allergy to
penicillin can be treated with the drug when
indicated, and it should be given by the oral
route
 The patient is observed for 30 minutes after the first
dose, if possible, and is advised to seek immediate
care if any of the signs or symptoms of an allergic
reaction occur after he or she has left the dental
office

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Analgesics
 Aspirin may cause gastrointestinal upset, but this
problem can be avoided if it is taken with food or
a glass of milk
 Aspirin should not be used by patients with an ulcer,
gastritis, or a hiatal hernia, and should be used with care
by patients whose condition predisposes them to nausea,
vomiting, dyspepsia, or gastric ulceration
 Aspirin also is known to prolong prothrombin time and to
inhibit platelet function, which is usually of little clinical
importance except in patients with a hemorrhagic disease
or a peptic ulcer

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Analgesics (cont’d)
 Many people are allergic to salicylates
 Aspirin provokes a severe reaction in some patients
with asthma
 They may react in the same way to other
nonsteroidal anti-inflammatory drugs (NSAIDs) that
inhibit cyclooxygenase, the key enzyme involved in
the generation of prostaglandin from arachidonic
acid
 Most patients with asthma who react to NSAIDs also
have nasal polyps and nasal eosinophilia

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Analgesics (cont’d)
 Many NSAIDs are available and most can cause
some degree of gastrointestinal irritation
 NSAIDs should not be given to certain patients with
asthma, patients with an ulcer or hemorrhagic disease,
and those who are pregnant or nursing
 Codeine is a narcotic analgesic that commonly is
used in dentistry
 Emesis, nausea, and constipation may occur with
analgesic doses of codeine
 Most of the reported reactions to codeine consist of
nonallergic gastrointestinal manifestations (nevertheless,
these may be severe enough to preclude the use of
codeine in certain patients)

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Dental Materials and Products
 Type I, type III, and type IV hypersensitivity
reactions have been reported to result from
various dental materials and products
 Topical anesthetic agents have been reported to cause
type I reactions consisting of urticarial swelling
 Mouth rinses and toothpastes containing phenolic
compounds, antiseptics, astringents, or flavoring agents
have been known to cause type I, type III, or type IV
hypersensitivity reactions involving the oral mucosa or
lips
 Hand soaps and some dental agents also have been
reported as a cause of type IV reactions

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Latex Rubber Products
 A number of reports have demonstrated that
certain health care workers and patients are at
risk for hypersensitivity reactions to latex or
agents used in the production of rubber gloves or
related materials (e.g., rubber dams, blood
pressure cuff, catheters)
 Although most cases in health providers are type IV
reactions, serious type I reactions may occur in
physicians, dentists, other health care workers, and
patients as a result of contact with latex products such as
gloves, rubber dams, or catheters

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Latex Rubber Products (cont’d)
 Dentists should be aware that latex allergy
can manifest as anaphylaxis during dental
work when the patient or the dentist has been
sensitized to latex
 Studies have shown that latex-allergic persons have
IgE antibodies for specific latex proteins
 Nitrile gloves should be considered for use to
minimize these adverse reactions to latex proteins

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Hereditary Angioedema
 Hereditary angioedema is a condition that can be
provoked by infection, stress, dental surgery or
trauma and is best managed by implementation
of preventive measures
 Androgens such as danazol and stanozolol, which
increase hepatic production of C1 inhibitor, help to
decrease the number and severity of attacks
 Newer agents that include C1 inhibitor concentrate
(Cinryze or Berinert) show benefit but are expensive
 Use of such preventive agents is important, because
hereditary angioedema does not respond well to
epinephrine or antihistamines

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Treatment Planning Modifications
 The dentist should obtain from each patient a
history of any allergic reactions
 If a patient has a history of allergy to drugs or
materials that may be used in dentistry, a clear entry
should be made in the dental record, and any further
contact with or use of the antigen(s) should be
avoided
 Most allergic patients can receive any indicated
dental treatment so long as the antigen is avoided
and precautions are taken for patients receiving
steroid or those known to have angioedema

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Type I Hypersensitivity
 Oral lesions can be produced by type I
hypersensitivity reactions
 Atopic reactions to various foods, drugs, or anesthetic
agents may occur within or around the oral cavity and
usually are characterized by urticarial swelling or
angioedema
 The reaction generally is rapid, with soft tissue swelling
within a short time after contact with the antigen
 Oral antihistamines should be given (oral
diphenhydramine, 50 mg every 4 hours, is the
recommended regimen)
 Further contact with the antigen must be avoided

60
Type III Hypersensitivity
 Food, drugs, or agents that are placed within
the oral cavity can cause white,
erythematous, or ulcerative lesions as
determined by the presence of type III
hypersensitivity or immune complex reactions
 These lesions usually develop within 24-hours after
contact is made with the offending antigen
 Some cases of aphthous stomatitis may be caused
by type III hypersensitivity, but more are related to
an immune dysfunction that has not been fully
characterized

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Type III Hypersensitivity (cont’d)
 Erythema multiforme represents an immune
complex reaction that appears as
polymorphous eruption of macules, erosions,
and characteristic “target” lesions that are
symmetrically distributed on the skin and/or
mucosa
 About half of the patients in whom erythema
multiforme is diagnosed are found to have a
predisposing factor, such as a drug allergy or a
herpes simplex infection, that is involved with the
onset of their disease

62
Type III Hypersensitivity (cont’d)
 Many patients with erythema multiforme can
be treated with symptomatic therapy,
including a bland mouth rinse, syrup of
diphenhydramine, and topical or systemic
corticosteroids
 If a drug appears to be associated with onset of the
disease, the drug should be withdrawn and any
further contact with it should be avoided

63
Type IV Hypersensitivity
 Contact stomatitis is a delayed allergic
reaction that is associated with the cellular
immune response in most cases
 In many cases, no further treatment is necessary
once the source of the antigen has been identified
and removed from further contact with the patient
 If the tissue reaction is severe or persistent, topical
corticosteroids should be used

64
 Various dental materials, such as those used
to make impressions, have been reported as
the cause of allergic reactions in patients
 Impression materials containing aromatic sulfonate
catalyst have been reported to cause a delayed
allergic reaction in postmenopausal women
 The reactive lesion consisted of tissue ulceration
and necrosis that became progressively worse with
each exposure

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 Some investigators have reported oral lesions
may be found in close association with
amalgam restorations
 These (mucosal) lesions have been described as
whitish, reddish, ulcerative, or “lichenoid,” and were
thought to be caused by toxic irritation or a
hypersensitivity reaction to the silver amalgam
restoration
 Reports have suggested that some of the oral
lesions resulted from toxic injury to the mucosa, and
others were a result of type IV hypersensitivity
reaction to mercury in the amalgam

66
 No thorough studies have correlated
nonspecific symptoms such as depression,
fatigue, and headache with the effects of
mercury in amalgam restorations
 The practice of avoiding the use of amalgam
restorations in patients with nonspecific symptoms
has, at present, no scientific basis
 However, removal of any amalgam restorations in
contact with oral mucosa that shows lesions
consistent with a toxic or hypersensitivity reaction to
mercury is rational

67
 On rare occasions, dental composite
materials have been reported to cause
allergic reactions
 The acrylic monomer used in denture construction
may cause an allergic reaction (however, the vast
majority of tissue changes under dentures result
from trauma and secondary infections with bacteria
or fungi)
 Gold, nickel, and mercury have been reported to
cause allergic reactions that result in tissue
erythema and ulceration

68
 The dentist may wish to test agents that are
thought to be possible antigens that cause
oral lesions
 In most cases, a reaction is not expected to develop
for at least 48 to 72 hours
 Skin testing and oral epimucous testing for potential
antigens are not foolproof, by any means (in certain
patients, they yield unreliable tissue responses)

69
 Basic management of contact stomatitis
requires removal of common sources of
antigens known to cause hypersensitivity
reactions and assessment for lesion healing
 Skin or mucosal testing for sensitivity also can be
performed
 If the lesions persist, topical steroids can be applied

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Lichenoid Drug Eruptions
 Some patients with skin or oral lesions
identical to those of lichen planus will be
found to have taken certain drugs before
appearance of the lesions
 The agents most commonly associated with the
onset of lichenoid lesions are levamisole (Levantine)
and the quinidine drugs
 Biopsy specimens of a lichenoid lesion show a
microscopic picture similar to that seen in lichen
planus, with the additional finding of eosinophils in
the subepithelial infiltrate

71
Management of SevereType I
Hypersensitivity Reactions
 Even when the dentist has taken appropriate
precautions, an allergic reaction may occur
 In handling the anaphylactic reaction, the dentist
should remember that it has an allergic origin
 The reaction occurs soon (within minutes) after
injection, ingestion, or application of a topical
anesthetic, medication, local anesthetic, or dental
product

72
Management of SevereType I
Hypersensitivity Reactions (cont’d)
 The dentist must take the following actions
immediately
 Place the patient in a head-down or supine position
 Make certain the airway is open
 Administer oxygen
 Be prepared to send for help and to support
respiration and circulation
 If these initial steps have not resolved the
emergency situation, and the cause is highly likely to
be allergic, the dentist is faced with an edematous-
type or anaphylactic reaction

73
Angioedema
 The dentist must take additional emergency
steps to prevent death from respiratory failure
 Activate emergency medical service (EMS)
 Inject 0.3 to 0.5 mL of 1:1,000 epinephrine by an
intramuscular (into the tongue) or subcutaneous
route
 Supplement with intravenous diphenhydramine (50
to 100 mg) if needed

74
Angioedema (cont’d)
 Additional emergency steps to prevent death
from respiratory failure (continued)
 Support respiration, if indicated, by mouth-to-mouth
breathing or bag and mask (the dentist should make
sure the chest moves when either of these methods
is used)
 Check the carotid or femoral pulse (if a pulse cannot
be detected, closed-chest cardiac massage should
be initiated)
 Confirm that emergency medical service is on their
way, and transport to medical facility if needed

75
Anaphylaxis
 An anaphylactic reaction usually takes place
within minutes but may take longer
 In contrast to a severe edematous reaction, in which
respiratory depression occurs first, both respiratory
and circulatory components of depression occur
early in the anaphylactic reaction

77
Questions to Ask Patient
■ Are you allergic to anything? If so, what are you allergic to?
■ What kind of symptoms did you have when you experienced
this allergic reaction?
■ How long ago was this allergic reaction?
■ If patient believes he/she had a reaction to local anesthetic but
cannot remember what it was, ask who their previous dentist
was and attempt to contact them.
■ Have you ever been to an allergist and received provocative
drug testing?

78
Dental Products to
Recommend to Patient
■ Fluoridated products (dentifrices, mouth rinses)
■ Dy mouth products for patients experiencing xerostomia
■ If patient presents with nut allergy, recommend fluoride gel
trays, rather than fluoride varnish.
■ If patient presents with milk allergy, avoid MI paste. (Milk-
protein derivatives) Recommend Sensodyne.

Chapter 19 Allergy

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Chapter 19 Allergy