Chapter 16: Allergic and Immune Disorders Flashcards
Definition of anaphylaxis
Overwhelming, immediate systemic reaction due to IgE-mediated release of mediators from tissue mast cells and peripheral blood basophils
Epidemiology of Anaphylaxis
Responsible for 500-1000 fatalities yearly
Causes can be food, medication, insect, latex, exercise, or idiopathic
Course of disease of Anaphylaxis
Mild reactions may occur with only scattered hives, puritus, and/or nausea
Significant reactions include widespread hives, tongue/lip/throat swelling, wheezing, coughing, stridor, vomiting/diarrhea, anaphylactic shock
What is biphasic reaction of anaphylaxis?
Patients have symptoms recurring 2-8 hours up to 72 hours later
Significance of asthma and anaphylaxis
Patients with asthma are at greater risk for severe reaction
Diagnosis of Anaphylaxis
Other conditions may appear similar (vasovagal reaction, flushing episode, anxiety, cardiac events)
Look for a triggering event within 2 hours of onset
If in doubt, treat for anaphylaxis to prevent serious consequences
Dental Considerations for Anaphylaxis
Identify known allergies prior to treatment
Avoid known allergens and any material/drug with cross-reactivity
Prompt recognition of anaphylaxis is critical
Appropriate emergency management drugs should be immediately available
Allergic Rhinitis Clinical Presentation
Seasonal or perennial in nature
Nasal congestion, nonpurulent rhinorrhea, sneezing
Puritis of eyes, nose and palate
Etiology of allergic rhinitis
Inflammation of nasal mucous membranes resulting from IgE-mediated allergic reaction to protein/glycoprotein of inhaled aeroallergen
Diagnosis of allergic rhinitis
Focused history
Physical exam with correlation of symptoms with positive skin-prick test
Management of allergic rhinitis
Avoid inciting allergens
Pharmacotherapy: antihistamines, intranasal corticosteroids, decongestants
Immunotherapy for patients who do note receive adequate relief from pharmacotherapy
For patients with comorbidities (asthma, chronic otitis media, sinusitis) specific treatment targeted to those medical conditions
Complications of allergic rhinitis
Acute/chronic sinusitis
Recurrent otitis media with eustachian tube dysfunction and hearing loss
Impaired speech development
Nasal polyps
Sleep apnea
Increased likelihood of developing asthma or aggravation of existing asthma
Dental considerations of allergic rhinitis
None with adequate symptom relief
In severe cases, mouth breathing may predispose to alterations of facial growth
Mouth breathing without a diagnosis should alert dentist to allergic rhinitis - refer to allergist
May consider consulting ENT if considering sedation and airway patency is a concern
Atopic Dermatitis Clinical Presentaiton
Chronic dermatitis characterized by puritis and relapsing inflammation
Typical lesions begin acutely with erythema and excoriations triggered by scratching
Uncontrolled itching and rash takes chronic appearance of lichenification and hyperpigmentation without erythema
Affects infants/young children on extremities, cheeks, forehead, neck
Affects older children in flexural areas (knee and elbow)
Etiology of Atopic Dermatitis (atopic eczema)
Distinct causal relationships are ill-defined
Sensitization to foods or aeroallergens may contribute
1/3 of cases may be exacerbated by at least one food
Strong familial atopic association exists including those with asthma and allergic rhinitis
Diagnosis of atopic dermatitis
Made by history and physical examination
90% of cases present before age 5, most resolve by puberty
Diagnostic criteria include puritis, pattern of skin involvement, history of atopic disease, age, elevated serum IgE
Many diseases present with similar lesions as atopic dermatitis
Management of atopic dermatitis
Education: trigger avoidance
SKin hydration
Itch control (antihistamines), topical steroids for flares
Newer steroid sparing anti-inflammatory therapies used with caution in children
Dental considerations for atopic dermatitis
None except for patients on high dose corticosteroids which necessitates consultation with physician
Clinical presentation of urticaria
Extremely puruitic, erythematous, raised lesions affecting the superficial dermal layers that blanch with pressure
Associated with angioedema in 40% of cases
Acute urticaria typically lasts less than 6 weeks and has a trigger, chronic is idiopathic and lasts longer
Clinical presentation of angioedema
Swelling is deeper and primarily affects face, extremities, genitalia with occasional tongue enlargement or laryngeal edema
Diagnosis of urticaria and angioedema
Depends on focused clinical history, identifying triggers and systems review
Further workup includes blood tests, biopsy
Management of urticaria and angioedema
Avoid triggers
Antihistamines
In severe refractory cases, oral steroids
Dental considerations of urticaria and angioedema
Avoid treating patients in active phase
Be aware of any medication triggers
Hereditary Angioedema
Etiology: autosomal dominant disorder resulting from deficiency in functional C1 Esterase inhiibtor
Submucous or subcutaneous edema lasting for 2-5 days before spontaneously resolving
Triggered by trauma, medical/dental, emotional stress, menstruation, infections, medication
Non-pitting, tensely swollen, painful, non-erythematous
Most common areas are lips, eyelids, tongue, genitalia, extremities
Management of Hereditary Angioedema - Prophylaxis
Prophylaxis
- daily anabolic attenuated androgens used to be only therapy
- Purified C1-Esterase Inhibitor is approved for routine prophylaxis of attacks for patients above 16 years
- Fresh frozen plasma occasionally used before major surgical procedures
Management of Hereditary Angioedema - Acute Attack
Purified C1-Esterase inhibitor for above 16 years
Ecallantide for above 16 years
Rapid administration of anabolic steroids is no longer preferred
Tracheotomy may be potentially lifesaving
Epinephrine and antihistamines are NOT useful
Dental considerations of hereditary angioedema
Routinely well-managed patient is not a contraindication for dental treatment
Some perioral swelling may occur following dental procedures; this should not discourage dentist from seeing these patients
Food Allergy - clinical presentation
Cutaneous reactions include urticaria, angioedema
GI manifestations especially in children
Oral symptoms include tongue, lip and perioral edema and pruritis of palate or lips
Sneezing, rhinorrhea, nasal pruritis, bronchoconstriction are signs of generalized anaphylactic reaction
Etiology of Food Allergy
Aberrant immune response induced by exposure to particular food protein
May be IgE-mediated, cell-mediated, or both
IgE meaited 6-8% of children <3 years
Overall prevalence in general population s 2%
Common food allergens in children
Eggs Peanuts* Cow milk Soy Tree nuts* Fish* Shellfish* Wheat
*indicated allergies that persist into adulthood; others may be grown out of
Is there a relationship between food allergies and atopic dermatitis?
Yes - 35% of children with moderate to severe atopic dermatitis have confirmed food allergies
Diagnosis of food allergies
Thorough history
Temporal association
Reproducibility of symptoms on every exposure
Clinical features
Diet history and ingredient labels need careful review
Skin-Prick-Tests or blood test confirm IgE mediated food allergy
True food allergy is distinguished from food intolerance (lactose, gluten, food additives) which are often limited to GI symptoms
Management of food allergies
Avoidance is key principle
Read labels carefully for hidden ingredients
Patients should carry epipen at all times
Dental considerations for food allergies
Avoid major food allergens when making dietary recommendations
Children, especially those highly sensitized to peanuts, may react to air-borne food allergens and even to contact from someone who has recently consumed these products
Latex Allergy Etiology and Pathogenesis
Reaction to certain proteins in latex rubber
Amount of latex exposure needed to produce sensitization is unknown
Latex products manufactured from milky fluid derived from rubber tree
True prevalence is unknown, with estimates of general population 5-10% and healthcare workers 0.5-17%
Clinical presentation of latex allergy
Irritant contact dermatitis (ICD)
Allergic contact dermatitis (ACD)
Immediate allergic reaction
Irritant Contact Dermatitis
Non-immunological mediated dermatitis characterized by dry, itchy, irritated areas of skin, usually of the hands
Causative factors: maceration and abrasion from glove wearing, repeated hand washing, use of cleaners/sanitizers, exposure to powders in gloves
Allergic Contact Dermatitis
Delayed hypersensitivity reaction caused by accelerators, promoters, and antioxidants added to natural rubber latex
T-cell mediated response
Rash, redness, itching 24-28 hours after contact
Rash may progress to oozing skin blisters and may spread to skin untouched by latex
How to differentiate between ICD (irritant contact dermatitis) and ACD (allergic contact dermatitis)?
Allergy patch testing distinguishes Type IV hypersensitivity reaction of ACD from non-allergic reaction of ICD