Hypersensitivity: Dental Management Flashcards
(22 cards)
What are the roles of dentists regarding patients who have allergies?
- identify patients with true allergies
- recognize oral soft tissue changes due to allergic reactions
-modify dental care as needed - recognize/manage acute allergic reactions
what percentage of Americans are allergic to something?
25%
what are the hypersensitivity reaction types and what causes them?
Humoral
- Type I: IgE mediated; antibiotics and local anesthetics
- Type II: IgG mediated
- Type III: immune complex mediated
Cellular
- Type IV: cell mediated or delayed; dental materials , TB tests, autoimmune, transplant rejections, graft vs host and contact dermatitis
what is a type I IgE mediated hypersensitivity reaction and what are the main symptoms?
immediate response that releases histamine, leukotrienes and interleukins and causes vascular dilation, endothelial leakage and smooth muscle contractions
- urticaria
- angioedema
- anaphylaxis
what are the main causes of Type I anaphylaxis?
- antibiotics (penicillins, sulfonamides, cephalosporins etc)
- local anesthetics
- latex allergy (mainly type IV sometimes type I)
what are the main causes of Type I urticaria and what do you tell patients to do if it occurs?
- main cause in adults is drug reactions
- stop antibiotics if rash or hives occur, go to ER if there is difficulty breathing
what are the main causes of Type I angioedema?
- type I acquired histamine reaction from from antigen contact (food allergies)
- drug induced from impaired bradykinin degradation (ACE or ARB drugs)
what would be the management for a mild angioedema reaction?
if only the lips and eyelids are involved then
- 50 mg of diphenhydramine (benadryl)
what would be the management for a severe angioedema reaction?
if tongue, pharynx or larynx and respiratory distress is involved emergency treatment includes
- 0.5ml or 1:1000 epinephrine and oxygen
- then 50 mg of diphenhydramine
what are the most common causes of anaphylactic death?
penicillin
bee stings
wasp stings
peanuts
what would be the management for a severe anaphylaxis reaction?
- patient in supine
- identify and call 911
- check airway
- oxygen
- check respiratory, pulse, BP and if depressed give epipen
why do we give epinephrine for anaphylactic shock?
- relaxes bronchial smooth muscles
- improves cardiac output
- reduces vascular permeability
how common are latex allergies?
- 1-6% in the general public
- 5-18% of healthcare workers
what are the percentages of patients that have a penicillin drug reaction and what route of administration is the main cause?
- 5-10% of patients
- topical
what drugs must you avoid with penicillin allergies due to cross reactions?
- ampicillin
- penicillinase
- cloxacillin
- carbenicillin
- methicillin
- cephalosporins
- use macrolides or clindamycin
what drugs are used for infective endocarditis prophylaxis and what if there is a history of anaphylaxis ?
- use cephalexin, azithromycin, clarithromycin or doxycycline
- do not use cephalexin if there is anaphylactic history
what are the types of reactions from local anesthetics?
- toxic reactions
- vasoconstrictor effects
- anxiety (fainting)
- true allergy to amides are rare
what are the symptoms of a toxic reaction to local anesthetics?
- talkativeness
- slurred speech
- dizziness
- nausea
- depression
- euphoria
- excitement
- convulsions
what is the local anesthetic that has the highest rate of allergic reactions?
procaine (novocaine)
what are the main cross reactions of local anesthetic allergies?
- benzoic acid esters
- usually none between the amides
- none between esters and amides
- methylparaben preservatives in multi dose vials of lidocaine and procaine
what is the management for local anesthetics?
- obtain careful history
if anesthetic that caused reaction is unknown - refer patient to allergist for skin testing and PDT
- use antihistamines for anesthesia
what is antihistamine as anesthetic?
1-4ml of diphenhydramine with 1:100,000 epi with a max dose of 50 mg for 30 min of anesthesia
