Allergy/ immunology Flashcards
By what route should you administer epinephrine for anaphylaxis
IM
How often can IM epinephrine be given for anaphylaxis?
every 5 to 15 minutes
what is the dose of IM epinephrine
0.01 mg/kg to max of 0.5mg
why is subcutaneous epinephrine not recommended for anaphylaxis
causes local vasoconstriction which may inhibit absorption
when should you consider IV epinephrine
repeated doses of IM epi (typically after 3 doses)
persistent hypotension despite fluid boluses
patients on beta blockers may be resistant to epinephrine, what medication should you consider?
glucagon
what are 5 second line agents for anaphylaxis
- salbutamol
- nebulizer epinephrine
- H1- antihistamines
- H2- ranitidine
- corticosteroids
what is the risk of having a biphasic reaction
5-20%
when do most biphasic reactions occur
4-6h but can occur up to 72 hours
name 3 factors that increase your risk of having a biphasic reaction
more than one dose of epinephrine
delayed administration of epinephrine
severe symptoms at presentation
what are the 3 most common causes of anaphylaxis in children
food
venom
medications
what is required at discharge for a pt with anaphylaxis
epipen referral to allergist anaphylaxis action plan medical alert bracelet avoid trigger consider 3 day course of antihistamines and corticosteroids
what are the most common food allergies (8)
milk egg peanuts tree nuts shell fish fish wheat soy
what are the advantages of a skin prick test (4)
results within 15 minutes
more sensitive then serum specific IgE
cost effective
high negative predictive value
what are the disadvantages of a skin prick test (4)
false positives (up to 50%)
affected by the use of antihistamines and corticosteroids
cannot perform if skin disease at the skin
risk of systemic reaction (although low)
what are the advantages of serum specific IgE (3)
not affected by antihistamines and corticosteroids
no risk of systemic reaction
can be performed if the patient has skin disease
what are the disadvantages of serum specific IgE (3)
false positives if elevated total IgE
more expensive then skin prick test
less sensitive compared to skin prick test
what percentage of children outgrow cows milk protein and egg allergy? peanuts?
80% of children outgrow cow’s milk protein and egg allergy
20 % of children outgrow peanut allergy
how should you manage someone with food allergy
Avoidance of responsible food Oral immunotherapy offered in some centers Epinephrine auto-injector Anaphylaxis action plan Medical identification device
what conditions do we use immunotherapy for? (4)
venom allergy
allergic rhinitis
allergic asthma
atopic dermatitis with aeroallergen sensitivity
what is the typical injection schedule for immunotherapy
weekly injections for 6 months (build up phase) followed
by monthly injection for 5 years (maintenance phase)
What is cross reactivity between penicillin and
cephalosporins?
2%
what is the dose for epipen jr and the weight we use it for
0.15mg
10-25kg
what is the dose for epipen and the weight we use it for
0.3mg
>25kg
what are the 3 receptors that epinephrine works on
a1
b1
b2
What is the first line treatment for chronic urticaria
standard dosing non sedating second generation antihistamine
what is the second line treatment for chronic urticaria
increase the dose of non sedating second generation antihistamine 4 fold
what is the third line treatment for chronic urticaria
montelukast, cyclosporin, omalizumab, short dose of steroids (not more then 10 days)
what is the first line treatment for hereditary angioedema? second line?
C1 inhibitor concentrate
FFP
A child has received IVIG in the course of their treatment. How long should you wait before giving them vaccines to ensure adequate response?
8-11 months
what are the advantages of second generation antihistamines
less sedating faster onset once daily dosing less anticholinergic effect fewer drug interactions (do not significantly interact with cytochrome p450 system)
what is the mutation associated with hyper IgM syndrome
mutation in CD40 ligand (on x-chromosome)
important for cross talk between t and b cells
what are the laboratory features for hyper IgM syndrome
elevated IgM low IgA low IgG normal T and B cell numbers 50% have neutropenia poor antibody responses to vaccines
what is the treatment for hyper IgM syndrome
PJP prophylaxis
IVIG
HSCT- for immunodeficiency and to prevent malignancy
what type of infections are seen with Hyper IgM syndrome? what liver problems? malignancy?
Bacterial infections in 1st year of life
Opportunistic: PJP, Cryptococcus
Autoimmunity
• Cytopenias, arthritis, inflammatory bowel disease
Liver disease
• Sclerosing cholangitis
• Chronic hepatitis
Malignancy (lymphoma) later in life
what is Cartilage Hair Hypoplasia?
Short-limbed dwarfism and combined
immune deficiency
what is the clinical presentation of someone with cartilage hair hypoplasia
Short pudgy hands hyper-extensible joints sparse light hair Hirschsprung’s disease (in some) immunodeficiency (range from SCID to almost normal)
what type of immunodeficiency is IRAK4 Deficiency
innate immunodeficiency
what is Chronic Mucocutaneous Candidiasis
Persistent Candida infection in skin, nails & mucous membranes
what type of donor is required for Hematopoietic stem cell transplantation
HLA matched donor- ideally a sibling
Alternatively HLA-matched unrelated donor or cord donors
what are some adverse effects of IVIG
Risk of transmission of blood-borne infections
• Headache, myalgias, fevers, chills
• Aseptic meningitis, anaphylaxis, hemolytic anemia
• Thrombosis, renal complications
which PID are inherited in an autosomal dominant fashion (5)
- Hereditary angioedema (C1 inhibitor)
- Hyper IgE syndrome (STAT3)
- DiGeorge syndrome (22q11 microdeletion)
- Autoimmune lymphoproliferative syndrome (Fas)
- Chronic mucocutaneous candidiasis (STAT1)
which PID are inherited in an x-linked recessive fashion (8)
X-linked agammaglobulinemia (BTK)
X-linked SCID (IL2Rγ)
Hyper IgM syndrome (CD40 ligand)
Wiskott-Aldrich syndrome (WAS)
X-linked lymphoproliferative disease (SH2D1A)
IPEX (FoxP3)
X-linked chronic granulomatous disease (gp91phox)
X-linked dyskeratosis congenita (dyskerin)
what does IPEX stand for
Immune Dysregulation
• Infections not typically significant feature
Polyendocrinopathy
•Neonatal or infantile insulin dependent diabetes
Enteropathy
•Severe colitis
X-Linked
what is the mutation associated with IPEX
Mutations in FoxP3: defect in regulatory T
cells
what infection is seen with X-Linked Lymphoproliferative Disease
Selective inability to respond to EBV infection
75% develop severe/fatal infectious mononucleosis with
hepatic necrosis & bone marrow failure
List 3 Diseases of Immune Dysregulation
- Autoimmune Lymphoproliferative Syndrome (ALPS)
- IPEX
- X-linked lympophoproliferative disease (XLP)
what are symptoms of allergic rhinitis
nasal congestion rhinorrhea (clear and bilateral) sneezing postnasal drip (cough, throat clearing) ocular itch
what are some physical exam findings for allergic rhinitis
allergic shiners dennie Morgan lines allergic salute (horizontal line on nose) open mouth enlarged pale nasal turbintes cobblestonning in posterior oral pharynx
what are the treatment options for allergic rhinitis
allergen avoidance
intranasal corticosteroids (mometasone, fluticasone, ciclesonide)
second generation antihistamine (cetirtizine, loratadine)
leukotriene receptor antagonist (montelukast)
immunotherapy
type 1 hypersensitivity reactions are mediated by what cells
IgE mediated
how do you diagnose a penicillin allergy?
skin prick test (to major and minor determinants- 20 percent are due to minor determinants)
graded oral challenge
how do you treat acute graft versus host disease
Acute GVHD is usually treated with glucocorticoids; about 40-50% of patients show a complete response to steroids.
what are the manifestations of acute graft versus host disease
erythematous maculopapular rash
persistent anorexia
vomiting and/or diarrhea
liver disease with increased serum levels of bilirubin, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase
what are the two types of GVHD
acute GVHD- within 3 months
chronic GVHD- after 3 months
what are the manifestations of chronic graft versus host
Scleroderma-like, skin, joints, eyes, lungs, bone marrow, gut
if you are ordering IgG, IgM, IgA, IgE what must you order with it?
have to do albumin and total protein
if you are worried about T cell deficiency what must you rule out?
HIV
what is the long term treatment for hereditary angioedema
education on trigger avoidance (trauma, early and prompt recognition and treatment of oral/dental infection, meds (estrogens, ACE))
medical alert bracelet
written plan for acute attacks
hepB vaccine (incase they need blood products in the future)
long term prophylaxis:
c1 inhibitor concentrate
androgens
antifibrinloytics (TA)what is the difference in body surface area for SJS versus TEN
SJS<10%
TEN >30%
Tx= supportive
what is the rash that is seen with erythema multiforme?
target lesions
can sometimes have mucosal membrane involvement
what are the symptoms of serum sickness
Rash arthralgia / arthritis renal disease fever low complement
what is the treatment for serum sickness
Discontinue medication
NSAIDS, analgesics
Steroids, plasmapheresis for severe cases
what is the difference between serum sickness and serum sickness like?
there is NO renal disease
normal complement
serum sickness like is often caused by what two antibiotics
cefaclor
penicillin
How do patients with egg allergy get MMR, influenza vaccine and yellow fever?
¤ MMR vaccine: receive as single dose
¤ Inactivated influenza vaccine: receive as single dose with post vaccination monitoring same as any other vaccine
¤ Live attenuated influenza vaccine: receive as single dose
with post vaccination monitoring same as any other vaccine
¤ Yellow fever: requires skin testing with vaccine prior to
administration
what are some causes of acute urticaria?
food meds NSAIDS lasix venom
infection
idiopathic
what are some causes of chronic urticaria?
cold heat exercise water solar cholinergic vibration dermatographism idiopathic
how do patients with pollen food allergy syndrome present?
Oropharyngeal pruritus with ingestion of uncooked fruits, vegetables, spices, peanuts and tree nuts
what should a patient do if they have pollen food allergy syndrome?
Isolated oropharyngeal symptoms should avoid the raw foods but can have cooked foods
Systemic reactions should avoid all forms of the food and carry epinephrine auto-injector
what are the symptoms of DRESS (drug rash with eosinophilia and systemic symptoms)? what is the onset after drug?
Onset 1 - 8 weeks of drug exposure Rash eosinophilia hepatic dysfunction fever facial angioedema lymphadenopathy
what is the treatment for poison ivy dermatitis?
mid potency topical steroid for 2-3 weeks
what is the name for poison ivy and what is it caused by?
Rhus dermatitis (poison ivy, poison sumac, poison oak), a response to the plant allergen urushiol,
what is an example of a type 1 hypersensitivity reaction and what is the effector cell?
IgE
anaphylaxis
what is an example of type 3 hypersensitivity reaction and what is the effector cell?
immune complexes (antigen-antibody)- IgG or IgM
serum sickness
serum sickness like
SLE
what is an example of type 4 hypersensitivity reaction and what is the effector cell
T cell mediated (lymphocytes) contact dermatitis TB skin test SJS DRESS
what is the only immunoglobulin that crosses the placenta?
IgG
what is the innate immune system and what are 4 defensive barriers?
it is the first line defence to an intruding pathogen
- anatomic (skin, mucous membrane)
- physiologic (pH, temperature, chemical)
- Phagocytic (Neutrophils, monocytes, macrophages)
- inflammation
High tryptase can indicate what?
systemic mastocytosis
Acute graft versus host affects what 3 things?
skin, liver, GI tract
what are two common causes of erythema multiforme
HSV
Mycoplasma
what two medication classes cause SJS/TEN
sulfonamides
anticonvulsants
what class of medication is associated with DRESS
anticonvulsants
what causes hereditary angioedema
C1 esterase inhibitor deficiency
tx: C1 inhibitor (blood product)
what is an example of Type 2 hypersensitivity reaction
rh hemolytic disease of the newborn
what is the criteria for anaphylaxis?
Acute onset of an illness (minutes - hours) with involvement of the skin, mucosal tissue or both and at least one of the following:
Respiratory compromise
Reduced BP or associated symptoms of end-organ dysfunction
Two or more of the following that occur rapidly after exposure to a likely allergen for that patient:
Involvement of the skin-mucosal tissue
Respiratory compromise
Reduced BP or associated symptoms of end-organ dysfunction
Persistent gastrointestinal symptoms (eg, crampy abdominal pain or vomiting)
Reduced BP after exposure to a known allergen for that patient (minutes to hours)
Infants and children: low systolic BP (age specific) or greater than 30% decrease in systolic BP*
