15. Allergy To Dental Materials + Drugs Flashcards
LOs
allergen routes of entry
4 ROUTES OF ENTRY
- percutaneous/ mucosa
~ eg. plants / pet scratch - injection
~ eg. bee stings - inhalation
~ eg. hay fever (pollen) / asthma (dust) - ingestion
~ eg. food (nuts) / medicine
what is a allergic reaction vs toxic reaction?
- specific immune response?
- dose dependent?
ALLERGY
- an immunologically based sensitivity
* Specific immune response to the allergen
* Not dose dependent
* Reaction will change on subsequent exposure
TOXICITY
- a non-immunologically based reaction
* Non - specific, not immune
* Dose dependent
* May be accumulative
* Reaction will be similar on subsequent exposure
- what is hypersensitivity
- classifications?
1
* state of altered reactivity
* body reacts with an exaggerated immune
response to a foreign substance
2
* Hypersensitivity reactions classified as:
~ immediate type I
~ delayed IV
Type I hypersensitivity reaction
- Antigen binds to specific IgE
- IgE is bound to high affinity Fc receptors on mast cells
- Cross linking between IgE / Fc receptor complex causes degranulation
- release of histamine , serotonin , proteases , cytokines , leukotrienes - Chemical cascade attracts eosinophils , neutrophils and macrophages to site of antigen / antibody complex
- Leukotrienes and histamines induce vascular permeability
- causes smooth muscle contraction and bronchoconstriction
- extreme case = anaphylactic shock , wheezing
Type II hypersensitivity reaction
- mediated by IgG binding to antigen on cell or tissue surface
- IgG Fc binds to Fcy receptors of macrophages, NK (natural killer) cells
- IgG Fc also activates complement - opsonisation and activation of phagocytic cells
- degranulation or phagocytosis induces tissue damage
- mechanism in organ-specific disease (self-antigen or tissue)
Type III hypersensitivity reaction
- activation of complements
- activation of polymorphs
- antibody:antigen complex that occurs in circulation and settle down onto a cell membrane (particularly
kidneys)
Type IV hypersensitivity
- delayed type
- mediated by T cells (Th1, Th17, Tc)
- activated T cells secrete chemokines, cytokines
(IFN-y, TNF)to recruit and activate macrophages - activated macrophages secrete further proinflammatory cytokines (IL-12, TNF), tissue damage from degranulation
- formulation of granuloma: macrophages/ multinucleated giant cells, eosinophils, T cells, fibroblasts
- mechanism in organ-specific autoimmune disease
- not instantaneous
(TNF = tumour necrosing factor)
what are the types of hypersensitivity and what do they do?
- Type 1 – Immediate IgE mediated - Anaphylaxis
- Type 2 – Auto antibody mediated
- Type 3 – Immune complexes
- Type 4 – T cell mediated - Delayed hypersensitivity
Relevance of Allergy to Dentistry
Dental team
* Management + awareness of Anaphylaxis
* Contact dermatitis may affect staff
Patients
* Awareness of previous allergy
* Reduce exposure to potential allergens
Materials used in dentistry that could cause problems
*Drugs
~ Local anaesthetics
~ cortico-steroids
~ antibiotics
~ analgesics
- Restorative materials
~ Amalgams
~ Ionomers
~ Composites
~ Metals & Porcelains - Clinical materials
~ Latex
~ Impression materials - Tooth paste/mouth washes
what side effects can drugs cause on the oral mucosa
- Corticosteroids
- Methotrexate
- Gold
- Penecillamine
- Antimalarials
- NSAID’s
DRUGS SIDE EFFECTS
Corticosteroids candidosis
Methotrexate ulceration
Gold lichenoid reactions
Penecillamine loss of taste
Antimalarials lichenoid reactions
NSAID’s lichenoid reactions
(rarely), oral ulceration
Lichenoid reactions = white patches within the mouth that look like lichen planus
what is this?
what drugs may cause it?
lichenoid reactions
- nifedipine
~ used for hypertension - Salazopyrene
~ anti inflamm used in GI, reheumatology,
dermatology
what is this?
what drugs may cause it?
burn
- aspirin
what is this?
what drugs may cause it?
gingival hyperplasia
- nifedipine
~ hypertensions
oral reactions to toothpaste and mouthwashes
- Gingival desquamation (peeling)
- Gingival swelling & granulomatous (formed by T cell reactions) reactions
- Benign migratory glossitis
- Epithelial desquamation, inflammation
- Ulceration
oral reactions to Creams, Ointments, Impression materials
- Contact stomatitis
- Gingival desquamation, swelling & granulomatous
reactions - Mucosal Swelling
- Epithelial desquamation, inflammation
- ulceration
Adverse reactions to Local Anaesthetics (LEARN???)
- True allergy rare and accounts for <1% adverse
reactions - True allergy may be delayed as well as immediate
type - In UK 70 million dental LA given annually
- Adverse reactions to lignocaine & prilocaine
preparations reported to CSM over 25 year period
was 249 and included 9 deaths - LA account for 5-10% of adverse reactions to
anaesthetics drugs - Adverse effects are
- Associated with blocking ion channels in cell
membranes (CVS and CNS toxicity) - Due to other effects of drug or vehicle (mainly
peripheral nerve complications - Allergic reactions (often a mistaken diagnosis)
- Mechanical or other effects of technique such as
needle trauma or introduction of infection - need to work out if was truly an allergic reaction or caused by something else
Adverse reactions to Local Anaesthetics
reasons for referral to LA allergy testing clinics
(LEARN???)
- Collapse after LA (immediate or 2 hours later) (25%)
- Swelling of lips, eyes, cheeks, face (immediate and up to 2 hours later) (25%)
- Rash on chest, limbs, or contact area (1-7 hours later) (15%)
- Breathlessness, sweating, nausea, disorientation (10%)
- Headaches, irregular pulse and low BP.(8%)
- Swelling of throat, difficulty in breathing (8%)
- Behavioural changes (minutes to hours later) (5%)
- Sleepiness, dizzy (5%)
Skin tests for type 1 local anaesthetic allergy
Stage 1 : prick test
- small amount of LA dropped onto arm
- skin is pierced with a small needle to introduce a small dose
- helpful for highly sensitive patients
- not good discriminators of allergy alone
Stage 2 : intradermal
- 25 micrometres of LA introduced underneath the skin
- causes white area around test site caused by vasoconstriction of LA
- more positive outcomes
Stage 3: intrabuccal test
Conclusions
* Scratch skin tests alone are not good discriminators of allergy, intradermal tests are better discriminators
- Prilocaine produced more positive skin reactions than any other local anaesthetic agent tested
- In 95 of the 100 patients referred with suspected
anaphylactoid reactions to local anaesthetic agents, negative skin reactions to at least one of the agents allowed intrabuccal challenge and subsequent recommendation of an agent for future use - Skin testing, though not providing formal proof of allergy, provides a useful test to indicate local anaesthetics which may be used for future procedures
Type IV - hypersensitivity - contact hypersensitivity EGs to LA
- Contact sensitivity
- Mantoux skin test
- Homograft rejection
- involved in Orofacial granulomatosis (OFG)
how to find out what particular products / chem constitutions someone is allergic to
patch testing
using aluminium wells
Patches left in place for 48 hours
Results are read at 48 and 96 hours
Patches with immediate sensitivity are removed
What causes a lichenoid reaction on buccal mucosa ?
- lichenoid reaction to amalgam
Reactions to Latex
- Dental school staff and students at high risk of sensitisation (Tarbo et al 1997)
- less common now as latex free gloves
- Skin sensitisation
Dentists about 10%
General hospital staff 5-8%
Nurses 9%
Anaesthetists 16% - Sensitisation may worse in symptomatic asthmatics
- Percentages of new staff being sensitized will be less as no longer using powdered gloves
Latex allergy - Management
Non latex gloves
- plastic
- polyvinyl
Advise patients to carry non latex gloves with them
Polyurethane condoms
Latex policy in clinics
Specific RAST test
- skin scratch test with latex
Blood test
- check if IgE against latex is raised
Antihistamines
Epipen
- extreme , contains adrenaline for anaphylactic shock
Summary – Materials used in dentistry
- Medicines causing Anaphylaxis – covered in other lectures
- Medicines causing Mucosal reactions
- Local Anaesthetic reactions
- Contact sensitivity to dental materials
* Type 4 reaction
* Patch testing - Latex
causes of lip swelling
- Urticaria & Angioedema (specific fluid build up)
- Reactions to Foods
- Granulomatous conditions affecting the lips & oral cavity
- what is urticaria?
- signs and symptoms?
- how long does it clear away in?
- It sometimes occurs together with angioedema
1
Hives
2
* Wheals - spots or patches of raised red or white skin
* Wheals are usually itchy, painful or cause a burning sensation
3
* Usually clear away in a few hours, and are then replaced by other fresh wheals.
Angioedema
- signs and symptoms
- how long does it last?
- Often associated with autoimmune disease
1
* Angioedema is the name given to deeper swelling affecting the skin over the arms, legs, torso or face
- May also affect the tongue, mouth, throat and sometimes the upper airway
2
* Swellings commonly last for more than 24hrs, and usually there is no itching
Causes of Chronic Angioedema
- Food allergy (particularly nuts, shellfish, milk & eggs)
- Oral Allergy Syndrome
- Medicines
- Antibiotics
- Angiotensin –converting enzyme (ACE) Inhibitors -
Enalopril, Lisinopril etc:) - Angiotensin-2- receptor blockers (ARBs) – Irbesartan, Losartan etc:)
- Aspirin & NSAIDS
- Beta blockers
- Latex
- Hereditary (C1 esterase inhibitor deficiency)
~ Attacks triggered by – stress / injury/ surgery
/ dental treatment / pregnancy / medications
~ Often not possible to identify cause of
chronic angioedema - Associated with auto immune disease
Oral Cavity Reactions to Foods
- Usually type 1 sometimes type IV
- Oral cavity less sensitive than skin or nose
- Peanuts most common. (? Does cracking of nuts break through protective mucin coat)
- Other agents have been identified as causing problems
- Octyl gallate antioxidant preservative - sore tongue & erythema (Pemberton et al)
- Pumpkin seed -> swelling and Asthma (Fritsch et al)
Immediate Food Allergy
- what type of hypersensitivity reaction is it?
- small or large quantity of food?
- symptoms
- how long does it take for reaction to develop?
- diagnostic tests?
1
* Type I reaction - Anaphylaxis
2
* Small quantity food needed
3
* Perioral Erythema
* Lip Swelling
* Oral Itching
* Tongue + pharyngeal swelling
* Nausea + vomiting
4
* Reaction develops in minutes to hours
5
* Diagnostic skin tests available
Food Allergy
- Immediate - Type I
- Delayed
o Does it really exist? - Coeliac disease +
dermatitis herpetiformis well established =
delayed hypersensitivity
o Large quantity of food needed
o Develops in hours and weeks
o No diagnostic test except withdrawal & re-
challenge
Food intolerance
- Food intolerance (non-allergic hypersensitivity) is much more common
o Onset of symptoms is usually slower and may
be delayed by many hours after eating the
offending food
o Symptoms may also last for many hours, even
into the next day
o Intolerance to several foods or a group of
foods is not uncommon, and it can be much
more difficult to decide whether food
intolerance is the cause of chronic illness, and
which foods or substances may be responsible
Symptoms of Delayed Food Allergy
- Eczema
- Arthralgia
- Poor concentration / headaches / depression
- Irritable bowel syndrome / Crohn’s disease
- Urinary frequency
- Arthritis + rhinitis
Oral Allergy Syndrome / Pollen Food Syndrome
- cause?
- who develops
- type of hypersensitivity reaction
1
* Pollen allergens
* Birch most common
2
* Adults develop > children
* Usually occurs in people allergic to pollen from trees, grasses, weeds
- Proteins of similar structure in fruit
3
* Distinctive type 1 reaction following direct contact of food and oral mucosa
- Link to Orofacial granulomatosis patients?
Oral Allergy Syndrome (OAS)
- Oral allergy syndrome (OAS) is a common food-related allergic condition that develops in adults. OAS is connected to environmental allergies, such as hay fever
- Features of oral allergy include swelling of mouth, periorbital tissues, pharynx
- Birch allergy strongest association
- 20% of patients with OAS may be scratch positive to
apples, peaches, kiwifruit, and rarely chestnut, salami - Specific allergen Bet vI identified in birch and apples
- Most common foods usually apples, peaches, kiwi,
hazelnuts & almonds - Antigens inactivated by cooking
- Other pollen – food cross reactions
- Latex – Fruit Syndrome (Avacado, Banana, Mango)
oral facial granulomatosis causes
SUMMARY
Urticaria & Angioedema
* Causes of swelling around the face and mouth after dental treatment
Food allergy
* Immediate & Delayed
* Oral Allergy syndrome
Guidelines for the Management of these reactions
Establish provisional diagnosis:
~ Allergy, toxicity or physiological reaction
~ local anaesthetics, dental materials, food
additives, mouthwash, toothpastes, etc
- Previous history of reaction - mild/severe
- Onset - rapid/delayed -how soon after contact
- Type of symptoms - rash, oedema, conscious level,
breathing difficulties, oral ulcers - Previous management of reaction -
none/medication/hospitalisation
how to test for hypersensitivity reactions?
Immediate (Type I) reactions
* Allergy testing- scratch tests / intradermal /
intrabuccal challenges
* Serology
~ Mast Cell Tryptase Levels
~ Complement/C1 Esterase Inhibitor
~ Total IgE + Specific IgE (RAST tests)
* Other Routine blood tests
~ FBP / B12 / Folate / Ferritin
Delayed hypersensitivity (Type IV)
* Allergy testing - Patch tests
Complementary & Alternative Testing
- Leukocytotoxic Test
- IgG Elisa Test (not IgE RAST test)
- Applied kinesiology
- VEGA testing (Electrodermal testing)
- Hair analysis
- Auriculo-cardiac reflex
- Stools analysis for yeast & parasites
Management of patients
- If allergy not proven with allergy testing, clear typed letter to referrer of findings and diagnosis. Always copy to GP
- If allergy proven, give information to patient on proven allergens identified. Discharge from clinic with letter to referring GP/GDP
- Consider advice such as avoidance of precipitating allergen (suggest alternatives if possible, for LA)
- Use of MedicAlert badge
- Prophylactic antihistamines/corticosteroids
- Second generation non sedating – eg: Fexafenadine
- Prednisolone 10mg for severe acute attacks
- Availability of adrenaline (Epipen)/ emergency support services
SUMMARY
*Mechanisms present in oral cavity for all types of
allergic (hypersensitivity reactions)
- Established examples in oral cavity
~ Type 1 (Peanut)
~ Type 2 (Pemphigus)
~ Type 3 (Herpes & Erythema Multiforme)
~ Type 4 (Lichenoid)
*How to distinguish between allergy, toxicity and
pharmacological reactions
*What clinical / laboratory tests are helpfu
