Allergies Flashcards
What causes an allergic response?
B cells become hyperactive and increased amounts of immunoglobulins are produced causing a hypersensitivity
Hypersensitivity
an amplified or inappropriate response to an antigen leading to inflammation and destruction of healthy tissue
What are the two types of allergic reactions?
Atopic (local) and nonatopic disorders
Atopic disorders are characterized by what?
hereditary predisposition and production of local reaction to IgE antibodies
What are the 3 types of Atopic disorders?
- allergic rhinitis
- asthma
- atopic dermatitis/eczema
Nonatopic Reaction Examples
- tetanus vaccine
- insect venom
- airborne allergy
Nonatopic reactions lack what?
the genetic component and organ specificity of atopic disorders
A true latex allergy is considered to be what type of reaction?
type I hypersensitivity reaction
Contact dermatitis is considered to be what type of reaction?
type IV hypersensitivity reaction
Anaphylaxis
severe allergic reaction that is rapid onset and can cause various systemic reactions including death
Anaphylaxis is a clinical response to what type of reaction?
An immediate (type I hypersensitivity) immunologic reaction b/t specific antigen and an antibody
When does anaphylaxis occur?
when the body’s immune system produces specific IgE antibodies toward a substance that is normally nontoxic
When the body is re-exposed to the stimulating substance again it produces excess amounts of what protein?
histamine
Large amounts of histamine released in the body causes what?
- flushing
- urticaria
- angioedema
- hypotension
- bronchoconstriction
What are some common causes of Anaphylaxis?
- food
- medications
- other pharmaceutical/biologic agents
- insect stings
- latex
The severity of an anaphylactic reaction depends on what?
degree of allergy and dose of allergen
What are the three patterns of Anaphylactic reactions?
- uniphasic
- biphasic
- protracted
Uniphasic Reactions
occur as an exclusive incident where the patient develops symptoms w/in 30 minutes of exposure and resolve spontaneously w/in 1-2 hrs w/ or w/o meds
Biphasic Response
patient will have an initial reaction followed by subsequent symptoms up to 8 hours after
Biphasic response patients should be managed where?
emergency room
Protracted Response
may last for long period of time, up to 32 hours, and may include cardiogenic or septic shock and respiratory distress despite treatment
Mild systemic reactions consist of what symptoms?
- peripheral tingling
- sensation of warmth
- sensation of fullness in mouth/throat
- nasal congestion
- periorbital swelling
- pruritis
- sneezing
- tearing of eyes
Moderate systemic reactions may have what symptoms?
- flushing/warmth
- anxiety
- itching
- any of the milder symptoms
With more severe reactions you may see what?
- bronchospasm
- edema
- dyspnea
- cough
- wheezing
Mild and moderate reactions begin how long of exposure?
2 hours
Severe Systemic Reaction S/S
- abrupt onset w/ previous s/s
- bronchospasm
- larygeal edema
- severe dyspnea
- cyanosis
- hypotension
- dysphagia
- abdominal cramping
- n/v
- diarrhea
- seizures
What events may follow a severe systemic reaction?
cardiac arrest and coma
If the client is unable to avoid exposure to allergens they should be instructed to carry what?
Epinephrine
What route for medication administration is associated w/ the most severe anaphylactic reaction?
Parenteral
Insulin-allergic patients w/ diabetes and those allergic to penicillin may require what?
Desensitization
Desensitization
based on controlled anaphylaxis with a gradual release of mediators
What is the first line treatment of anaphylaxis?
Epinephrine
Why is Epinephrine the first line treatment?
it is the only medication that may halt cardiac or respiratory arrest
Cardiac or Respiratory Arrest typically occurs how long after exposure to allergen?
5-30 minutes
How is epinephrine given?
Sub q in the upper extremity or thigh
What other medications may be administered to prevent reoccurrence and to treat urticaria and angioedema?
Antihistamines and corticosteroids
Antihistamines take how long to suppress histamine levels by 50%?
80 minutes
If hypotension is unresponsive to vasopressors the nurse may administer what?
Glucagon
Rebound reactions typically occur how long after the initial reaction?
4-10 hours
How long are patients w/ severe reactions monitored in emergency unit?
12-14 hours
What emergency measures are taken to reduce severity of reaction and restore cardiovascular function?
- call provider
- intubation
- emergency meds
- IV lines
- fluids
- oxygen
Why may ET intubation be difficult or impossible w/ an acute allergic reaction?
b/c it can result in increased laryngeal edema, bleeding, and further narrowing of glottic opening
What type of intubation may be needed for Acute Allergic Reaction?
- fiberoptic ET intubation
- needle cricothyrotomy followed by trach
- cricothyrotomy
Allergic Rhinitis (Hay Fever/seasonal allergies)
- type I hypersensitivity reactions
- most common chronic respiratory allergic disease
- most common reason to visit doctor
- more common in children but rising in adults
Allergic Rhinitis often occurs w/ what other conditions?
- allergic conjunctivitis
- sinusitis
- asthma
If Allergic Rhinitis is left untreated what may occur?
- allergic asthma
- chronic nasal obstruction
- chronic otitis media w/ hearing loss
- anosmia
- orofacial dental deformities in children
Allergic Rhinitis is induced by what?
airborne pollens or molds
S/S of Allergic Rhinitis
- sneezing/nasal congestion
- clear,watery nasal discharge
- itchy eyes/nose
- lacrimation
- postnasal drip
- headache/pain over paranasal sinuses
Postnasal drip result in multiple attempts to clear airway causing what?
- dry cough
- hoarseness
- scratchy throat
Chronic Allergic Rhinitis can affect quality of life by causing what?
- fatigue
- loss of sleep
- poor concentration
- interference w/ physical activity
The greatest fear w/ allergic rhinitis is the development of what?
- persistent asthma
- chronic otitis media
- obstructive sleep apnea
- airway inflammation
What to see during physical exam diagnosis of patient for Allergic Rhinitis?
- allergic shiners
- puffy eyes
- clear/cloudy fluid arounf tympanic membrane
- rhinorrhea/congestion
- enlarged lymph nodes
- sinus tenderness
Diagnostic tests for Allergic Rhinitis
- nasal smears
- peripheral blood counts
- total serum IgE
- epicutaneous and intradermal tests
- RAST
What is the goal of therapy for Allergic Rhinitis?
provide relief of symptoms and encourage adherence to therapeutic regimens
Avoidance Therapy
every attempt is made to remove allergens that act as precipitating factors
What is the safest and most effective means of treating symptoms for Allergic Rhinitis?
Avoidance Therapy
When are oral antihistamines most effective?
when given at the first occurrence of symptoms b/c thet prevent development of new symptoms
Examples of Antihistamines
- benadryl
- claritin
- zyrtec
- xyzal
- clarinex
- allegra
Effectiveness of Antihistamines are limited to what patients?
- hay fever
- vasomotor rhinitis
- urticaria
- mild asthma
How do Adrenergic Agents help relieve severity of symptoms?
narrowing blood vessels in nasal passages therefor decreasing congestion
Adrenergic Agents will not treat what?
underlying cause
What is the most common oral Adrenergic Agent used?
Sudafed (pseudo-ephedrine hydrochloride)
When are Mast Cell Stabilizers used?
prophylactically to prevent onset of symptoms and treat symptoms once they occur
What is the most effective maintenance therapy for Chronic allergic rhinitis?
intranasal corticosteroids
Recommended use of ICS is limited to how long?
30 days
Immunotherapy
administration of gradually increasing quantities of specific allergens to patient until a dose is reached that is effective in reducing disease severity from natural exposure
Immunotherapy is treatment in the form of what?
vaccine therapy or sublingual meds
Allergy control by immunotherapy usually requires treatment for how long?
3-5 years
Therapeutic failure for Immunotherapy is evident when a patient doesn’t experience decrease in symptoms after how long?
12-24 months
Contact Dermatitis
- type IV delayed hypersensitivity reaction
- acute or chronic
- results from direct skin contact w/ chemicals or allergens
What are the 4 types of Contact Dermatitis?
- allergic
- irritant
- phototoxic
- photoallergic
S/S of Contact Dermatitis
- itching
- burning
- erythema
- skin lesions
- edema
- weeping, crusting, drying, and peeling of skin
- hemorrhagic bullae if severe
Atopic Dermatitis
type I immediate hypersensitivity disorder characterized by inflammation and hyperreactivity of skin often causing pruritus
What are the most consistent features of Atopic dermatitis?
pruritus and hyperiritability of skin most commonly in flexural folds
Atopic dermatitis is often the first step in the process that leads to what?
asthma and allergic rhinitis
“Allergic/Atopic Triad”
Guidelines for treating Atopic Dermatitis
- wear cotton fabrics
- washing with mild detergents
- humidifying dry heat
- using antihistamines
- avoiding allergens
What is the main treatment for Atopic Dermatitis?
keeping skin moisturized w/ daily baths and use of topical skin ointments
Dermatitis Medicamentosa (Drug Reactions)
type I hypersensitivity disorder applied to skin rashes associated w/ certain medications
S/S of Dermatitis Medicamentosa
- appear suddenly
- vivid color
- disappear rapidly after medication is withdrawn
What is Urticaria?
Hives
Urticaria
type I hypersensitive reaction characterized by sudden appearance of pinkish edematous elevations that cause itching/discomfort
How long do hives last?
remain for a few minutes to several hours
How long does do the hives have to come and go before a patient is diagnosed with Chronic Urticaria?
6 weeks
Angioneurotic Edema
involves deeper levels of the skin, resulting in more diffuse swelling rather than discrete lesions
S/S of Angioneurotic Edema
- no pitting
- skin may appear normal w/ reddish hue
- itching/burning sensations
- sudden swelling
- lips, eyelids, cheeks, hands, feet, genitalia, tongue
How does swelling appear with Angioneurotic Edema?
suddenly in a few seconds or minutes or slowly in 1-2 hours
Food allergies are thought to occur in who?
people w/ a genetic predisposition combined w/ exposure to allergen early in life
Most common food allergies are?
- seafood
- legumes (nuts)
- seeds
- berries
- egg whites
- buck wheat
- milk
- chocolate
S/S of Food Allergy
- urticaria
- dermatitis
- wheezing
- cough
- laryngeal/angio edema
- abdominal pain/cramps
- n/v
- diarrhea
Latex Allergy
allergic reaction to natural rubber proteins
Who is at most risk for Latex Allergy?
- health care workers
- patients w/ atopic allergies/multiple surgeries
- factory workers
- females
- spina bifida patients/SCI
Routes of exposure to latex are?
- cutaneous
- purcutaneous
- mucosal
- parenteral
- aerosol
