Immunology and allergies Flashcards
What type of allergic reaction (immune mediated pathway) is involved in hemolytic anemia?
Type II
What is first line therapy for eczema
Emolients and moisturizers
what is reaction triggered by binding of antigen to high affinity IgE receptor on the surface of mast cells, circulating basophils or both –> Release of histamine, leukotrienes, prostaglandins
Type I hypersensitivity
_______ Receptors in smooth muscle, endothelium and CNS tissue–> bronchoconstriction, bronchial smooth muscle contraction vasodilation, local pain/pruritis in type I hypersensitivity
histamine
Powerful bronchoconstrictor, sustains inflammation in type I hypersensitivity?
leukotriene
in type I hypersensitivity smooth muscle constriction, inflamm. mediation
prostaglandin
how are 4 ways allergens can be exposed in type I
Ingestion
Inhalation
Injection
Contact
how fast does type I occur
immediate or late phase - 2-4 hr past exposure
Reactions of Atopic dermatitis (eczema), urticaria, hay fever (allergic rhinitis), anaphylaxis, food allergies, PCN allergy are al what type of response?
type I
what ab mediates type I
IgE
what ab mediates type II
IgM, IgG or IgA binding to cell surface
what happens after ab binds ones own cells in type II
Activates complement pathway and B cell response
Lysis of cell or release of anaphylactoxins
Anaphylactoxins trigger mast cell degranulation
type II against RBC leads to
hemolytic anemia
type II against platelets leads to
thrombocytopenia
type II against thyroid cells leads to
graves disease
what is the rxn time for type II
hours to 1 day
ITP, hemolytic anemia, rheumatic fever, graves disease, myasthenia gravis are all what type of rxns
Type II
antibody cytotoxicity is what rxn?
type II
Immune complex is what type of rxn?
type III
what type has Antigen-antibody complex forms and via circulation deposit in tissue, blood vessels, filtering organs ( spleen, liver,kidney)
Type III
what type of rxn includes Serum Sickness
Henoch-Schonlein purpura
Post streptococcal glomerulonephritis
SLE
type III
Tissue injury by complement cascade and neutrophils that release toxic mediators
is part of what type of rxn
type III
what rxn is cellular immune mediated or delayed hypersensitivity
type IV
what rxn involves Recognition of antigen by sensitized T cells
type IV
what rxn involves: Contact allergies- Nickel, poison ivy, lotions, detergents Autoimmune- DM 1, hashimoto, MS, celiac disease
type IV
what is Chronic, relapsing, inflammatory skin condition
eczema or atopic dermatitis
what is the atopic triad
dermatitis allergic rhinitis and asthma
what type of hypersensitivity rxn is eczema
type I –> igE elevated
what is pruritis withErythematous papules assoc with excoriations, vesiculations?
atopic dermatitis
where is eczema found in young and infants
Facial and extensor involvement in infants and young children
whre is eczema found in older and adolescents?
Flexural lichenification
what is lesions in groin and axillary, linear
scabies
what has lack of pruritis, scalp locations, yellow scales
seborrheic dermatitis
what involves- distribution of lesions where substance touched
allergic contact dermatitis
how do we treat eczema 3
-hydration - baths, washcloths followed by occlusive agent
-moisturizers and occlusives - emolients, ointments (not lotion) , vaseline, olive oil,
-Topical corticosteroids - reduce inflammation and pruritis. Decreases Staph Aureus colonization
(fluticasone 0.05% cream in infants >3mo . stabilze, then twice/week)
(tacrolimus – immune modulator. 0.03% effective 2-15y, 0.1% > 15yr. Second line.)
what are Raised, red, itchy lesions on the skin that often come and go and can coalesce together in to larger, red, itchy areas. Unlike other rashes, these come and go and move about the skin. Superficial dermis.
hives - urticaria
what causes hives
occur from allergic reactions. These can be to medications but more commonly to something in the environment or a virus. In most situations of hives, we never determine the actual cause
what can be caused by physical changes in body temperature such as exposure to cold, heat or extreme exercise. Some people get when they are nervous. Bug bites can cause and so can the sun
hives
what is edema extending into deep dermis or subcutaneous tissues
angioedema
how long does it take for urticaria to resolve
hours (24hrs)
how long does it take for angioedema to resolve
72 hrs
what occurs most often urticaria angioedema or both
both>urticaria>angioedema
what is Rapid onset, serious allergic reaction in previously sensitized pt
anaphylaxis
what presents as Generalized pruritus, anxiety, urticaria, angioedema, throat fullness, dyspnea, hypotension, and collapse. May present with severe abdominal cramps, vomiting.
anaphylaxis
how do we treat anaphylaxis
epi
diphenhydramine IM of IV
Corticosteroids - prevent worsening
Vasopressors - hypotn
abx that most commonly cause SJS and TEN
Amox, Bactrim, Ampicillin
what is fever, rash, lymphadenopathy, myalgias and arthralgias (7-21 days if new, 1-4 if sensitized)
serum sickness
how do you tx serum sickness
antihistamines, epi, corticosteroids depending on sx
what is diff bw anaphyl and serum sickness
fever and delayed in ss
Immediate hypersensitivity reaction.
–>Allergic contact dermatitis 24-48 hrs after exposure
Spina Bifida unique sensitivity
latex
what is Common in young children epscially in first 3 yrs of life, highest prevalence found in children with moderate to severe atopic dermatitis
food allergies
what are the most common food allergens in young child
eggs, milk, peanuts, tree nuts, soy and wheat
what are most common food allergens in older child and may be life long
fish, shellfish, nuts
Reactions occur minutes to 2hrs after
hives, flushing, facial angioedema, mouth or throat itching.
GI sx - abdominal discomfort, nausea, vomiting, diarrhea –> what type of allergy?
food
what may result in urticaria, papulovesicular eruptions
cuteneous rxn to bug bites
what rxn with insect allergies cause?
Respiratory allergy due to inhalation of insect particles
Cutaneaous reactions to insect bites
urticaria, papulovesicular eruptions - mosquitos, fleas, bedbugs
Anaphylaxic reactions to stings
what bugs cuz anaphylaxis
almost exclusively hymenoptera stings
bees, wasps, yellow jackets, fire ants
treatments of insect allergies
cold compress, antihistamines, topical steroids, -epi
what type rxn is latex allergy
I
Transient Wheezing is common in infancy and during preschool Assoc with? 2
viral infections and smaller airways
Wheezing is a symptom what type of obstruction
lower airway
most common chronic disorders in childhood
asthma
what is found in asthmatic airways?
Inflammatory cells (mast cells, eosinophils, T lymphocytes, neutrophils), chemical mediators (histamine, leukotrienes, platelet-activating factor, bradykinin), and chemotactic factors (cytokines, eotaxin) mediate the underlying inflammation found in asthmatic airways.
what is CRADLE?
Causes of Cough in the First Months of Life:
C- CF
R – RTI
A- Aspiration (TEF,GER, swallowing dysfuntion)
D- Dyskinetic cilia
L – Lung or airway malformations (Laryngeal Web, vascular rings )
E- Edema ( heart failure, CHD)
the narrowing that occurs in asthma is caused by 3 things:
inflamm brochospasm and hypersensitivity
what is Reversible airway obstruction
asthma
risks of getting asthma? 4
history of atopy, viral infections of airways, exposure to tobacco smoke, family history
what are triggers of asthma? 10
allergies, pet dander, cold air, exercise, emotions, drugs, food, mold, GER, infection
what has Symptoms of intermittent dry cough, expiratory wheezing, shortness of breath, chest tightness, limited exercise tolerance
PE you find Expiratory wheezes, prolonged expiration, tachypnea, retractions, distress
asthma
what are the 3 categories of symptoms of asthma?
daytime exercise and nocturnal
what involvestussive spells, nocturnal dyspnea/chest tightness
nocturnal asthma
what involves cough, dyspnea, wheezing in response to:
Allergens, cold, heat, exercise, illness
daytime asthma
on CXR what shows Hyperinflation Flattening of diaphram peribronchial thickening prominence of pulmonary arteries areas of patchy atelectasis
asthma
asthma type: attacks nor more than twice a wk and nighttime attacks no more than twice a mo. attacks last no more than a fe hours to days. severity of attacks varies but no symptoms inbw
mild intermittent
asthma type: attacks more than twice a wk but not every dat and nighttime symptoms more than twice a mo. attacks are sometimes severe enough to interrupt regular activities
mild persistent
daily attacks and nighttime attacks more than once a wk. more sever attacks occur at least twice a wk and may last for 2 days. attacks require daily rescue medication and changes in daily activities
moderate persistent
frequent sever attacks, continual daytime symptoms, and frequent nighttime symptoms. require limits on daily activities
severe persistent
what has symptoms < 2day/wk or 2 nights/mo
peak flows > 80% of personal best
Treatment: no daily medications; bronchodilators prn
mild intermit
what has Symptoms > 2 day/wk but < qday, or > 2 nights/mo
peak flows > 80% of personal best
Treatment: daily low-dose inhaled corticosteroids
mild persistent
what has Daily symptoms or > 1 night/week
peak flows 60-80%
moderate persistant
what has Treatment: Daily low-dose inhaled corticosteroids AND
long acting inhaled beta2-agonist , or medium-dose inhaled corticosteroids
moderate persistent
what has Continual daytime symptoms and frequent symptoms at night
Peak flows < 60%
severe persistent
what hasTreatment: Daily high-dose inhaled corticosteroids AND
Long-acting inhaled beta2agonists AND
Oral corticosteroids with repeated attempts to wean when able
severe persistent
You see an 8 yr old in your office, with his mother who is concerned that he may have asthma. She also has asthma and his brother has eczema and allergic rhinitis. She has noticed that he has symptoms, mainly a cough, on 3 days of each week and has a night time cough once a week. Which of the following is the initial treatment for this child?
A low-dose inhaled corticosteroid
these are the first choice of treatment for all persistent forms of asthma
ICS
ICS prevent what
swelling in airways
Leukotriene inhibitors do what
inhibit mediators of inflammation and smooth muscle bronchoconstriction
leukotriene inhibitors also indicated for
allergy treatment
what are singulair and accolate
Leukotriene inhibitors
Adding a long-acting bronchodilator to inhaled corticosteroid therapy is more beneficial than
doubling dose of ICS
what do LABAs do?
relax airway smooth muscle ( never monotherapy)
Fluticasone/salmeterol =
advair
what work by relaxing bronchial smooth muscle within 5 to 10 minutes of administration. They last for 4 to 6 hours
shortacting bronchodilators - albuterol
what relieves bronchoconstriction, decreases mucus hypersecretion, and counteracts cough-receptor irritability
anticholinergic - ipratropim bromide
Asthma should be well controlled for at least ___months before stepping down therapy
3
A child with intermittent asthma has asthma symptoms how often
2 x/wk
daytime symptoms occurring two or more times per week or nighttime awakening two or more times per month implies a need
daily antiinflamm
preferred initial long-term control therapy for children of all ages
ICS
0 to 4 years of age, daily long-term control therapy is recommended for those who had
four or more episodes of wheezing in the previous year that lasted more than 1 day and affected sleep and who have a positive asthma predictive index
older than 5 years of age with moderate persistent asthma, combining long-acting bronchodilators with low-to-medium doses ICS
improves lung function and reduces rescue medication use.
a high-dose inhaled corticosteroid and a long-acting bronchodilator are the preferred therapy.
for children with severe persistent
A 3-year old male currently not on any asthma medications has visited your outpatient clinic 3 times in the past 6 months for acute wheezing, each episode lasting 2-3 days. In between episodes, his mother reports nighttime cough about 4 nights per month. This patient’s asthma severity can be BEST classified as:
Moderate Persistent Asthma (Step 3)
what is Life Threatening-May progress to respiratory Failure without prompt and aggressive treatment
Severe bronchospasm, excessive mucus secretion, inflammation, and edema of airways and not responsive to tx
status asthmaticus
what is FEV1 and pk flow for status asthmaticus
<50%
single most important lab determination in status asthmaticus
ABG
first line tx for status asthmaticus
inhaled B2 agonist - continuous neb
and
Humidified O2 (inadequate minute ventilation, V/Q mismatch)
what is also used in status asthmaticus?
Systemic Corticosteroids - decrease inflammation, stabilize mast cells, increase B2 receptor expression . IV route preferable
Inhaled anticholinergic bronchodilators - with albuterol maybe. Ir Ipatroprium Bromide. variable effectiveness
IV Beta agonists (terbutaline selective B2 agonsit) - smooth muscle relaxation
