Allergy/Immuno Flashcards
Number of infections concerning for IEI
Frequency red flags
4 new ear infections per year
2 serious sinus infectionsper year
2 pneumonia per year
2 serious deep seated systemic bacterial infections (total)
Loss of developmental milestones
Low IgA!
Ataxia telangectasia
Congenital cardiac disease
Hypocalcemia
Dysmorphic facies
DiGeorge
Wiskott Aldrich
Petechiae (thrombocytopenia), Bleeding
Eczema
high IgA and IgE
FTT
poor response to polysaccharide vaccines ex. pneumococcal
9 year old male with recurrent AOM, sinusitis, hearing loss. Has a history of hydrocephalus, and required CPAP at birth for respiratory distress. What is the most likely diagnosis?
primary ciliary dyskinesia
CVID
most common IEI
inability to produce specific antibodies - IgG MUST BE LOW
increased susceptibility to respiratory and GI infections (due to IgG and IgA deficiency)
Investigations show:
- Hypogammaglobulinemia with low serum levels of all class switched Ig’s (IgA, IgG, and IgE)
- Lack of vaccine titres despite vaccination
- Normal B/T cell numbers, but lack of class switched B cells
Tx: IVIG
HyperIgE Syndrome (Job Syndrome)
Triad: Recurrent staph skin abscesses, pneumonia, and very high IgE
“cold abscesses” - no fever
Other features:
Recurrent bacterial skin (staph boils) and pulmonary infections,
Chronic mucocutaneous candidiasis (non-invasive fungal infection),
very high serum IgE,
chronic eczematous dermatitis
Skeletal abnormalities (facial asymmetry, broad nose, deep set eyes, prominent forehead, scoliosis, delayed shedding of primary teeth)
primary ciliary dyskinesia
Autosomal recessive Genetic disorder resulting in either function of structure of cilia being compromised
Characterized by:
Recurrence U/LRTI
Bronchitis, recurrent rhinosinusitis,
frequent middle ear infections → hearing loss
Infertility
Aberrant organ laterality
CGD
x linked (males)
Presents with multiple abscesses and oral ulcers.
you have neutrophils but they don’t work (the neutrophils go to site of infection and just sit there creating an abscess)
At risk for Catalase positive organisms (staph aureus, serratia, pseudomonas, norcadia) and encapsulated organisms (Pseudomonas, Streptococcus pneumoniae, Haemophilus Influenzae type B, Neisseria meningitidis, Escherichia coli, Salmonella, Klebsiells, and group B Strep)
aspergillus is classic fungal infections
lymph nodes present
neutrophil oxidative burst (or DHR - dihyroxy rutabine)
Tx:
- Antibiotic prophylaxis
- HSCT is curative
Types of Immune reactions
Type 1 - IgE
Type 2 - Cytotoxic
Type 3 - Immune Complex
Type 4 - t cell mediated
Diagnosis of amoxicillin allergy
drug challenge test
skin testing for IgE poor predictive value
Ataxia Telangiectasia
- ataxia (progressive) & telangiectasia (around age 3-6) & frequent infections
- autosomal recessive; problems with DNA repair
- combined cellular and humoral imunodef –> recurrent sinopulm infections (most commonly absent IgA)
- high serum AFP
Bad reaction to live vaccines
T cell problem
–> look at lymphocytes
Description of a child with multiple abscesses, including lymph nodes and hepatic with serratia. which immunodeficiency?
CGD
Oral food allergy
- class 2 food allergen
- foods are cross reactive with pollens
- symptoms with raw food only (can tolerate cooked/processed foods)
- oropharyngeal symptoms only
- anaphylaxis is rare
- do a skin prick test for pollen
SCID
combined immunodef - both B and T cell function
x linked (male)
recurrent bacterial, viral and fungal infxn (opportunistic infxn - PJP)
usually presents early
Classics
- bad candida
- diarrhea
- FTT
- no lymph tissue (LNs or tonsils)
- no thymus on CXR
Labs
- CBC: lymphopenia
- flow cytometry: low t cells, now B cells
- abnormal mitogen stimulation assay (function of lymphocytes t cells)
- on NMS
CXR: no thymus
No live vaccines (ex. rota, MMRV)
Hereditary Angioedema
- autosomal dominant
- low function of C1 inhibitor leads to increased bradykinin production –> smooth muscle relaxation –> edema
- be cautious of laryngeal edema!!!
- don’t respond to epi, antihistamines or glucocorticoids
- often worsened in trauma, stress, menstruation, ACEi
Test:
- C4 will be low
- low C1 esterase inhibitor level and function
Treat:
- C1 INH or Bradykinin type 2 receptor antagonist
Serum sickness like reaction
type 3 hypersensitivity
Don’t form immune complex in serum sickness LIKE (you do form complexes in serum sickness)
Common triggers: amoxicillin, septra, vaccines)
Symptoms:
7-12 days post exposure
- rash
- fever
- arthralgias
- edema
Tx:
- stop the offending agent
- analgesis, NSAIDs, and antihistamine
- if severe, give steroids
10 signs of immunodeficiency
- 4+ ear infxn / yr
- 2+ sinus infxn / yr
- 2+ pneumonia / yr
- 2+ deep infxn/serious bacterial infxn
- 2+ months of abx with little effect
- Recurrent deep skin or organ abscesses
- Persistent fungal infxn (skin, thrush)
- IV abx
- FTT
- Family hx of primary immunodef
allergy testing
skin prick testing or specific IgE blood test (Aka RAST)
DONT test IgG
anaphylaxis epi dosing
0.01mg/kg of 1:1000 (1mg/ml) Intramuscular
tryptase level in anaphylaxis
should be elevated
if doing labs, send tryptase for patient with first episode of anaphyalxis from the ED
serum sickness like reactions
fever, rash and polyarthritis
typically sulfa drugs
less migratory compared to urticaria
usually 5-10 days after exposure
no mucous membrane involvement
management: stop the agent and do not rechallenge
skeeter syndrome
exquisite sensitivity to mosquito bites
bites can become inflamed or infected
worse at onset of season
responds to antihistamines
what is the most effective use for allergy immunotherapy?
bee stings
management FPIES
acute:
- ondans
- volume resus
Long term
- strict food avoidance
ex. stem child eats rice cereal for first time
confirming diagnosis of food allergy syndrome
skin prick testing to pollen
not life threatening
don’t need epi pen
poison ivy management
high potency topical steroids or po steroids if really bad
antihistamines not helpful
10 yo girl w/abdominal pain, u/s shows edema of the sigmoid colon & moderate free fluid in lower quadrants. On history, has had intermittent facial & left arm swelling over the last 5 years. Which test would reveal the diagnosis?
c1 esterase inhibitor level
9 year old male with recurrent AOM, sinusitis, hearing loss. Has a history of hydrocephalus, and required CPAP at birth for respiratory distress. What is the most likely diagnosis?
PCD
- hydrocephalus
- CPAP at birth (?TTN)
- hearing loss
- sinopulm infxn
A 6-year-old girl has a history of frequent infections. She also is off balance when walking and has skin telangiectasias. What is the most likely finding?
low IgA and high AFP
ataxia telangectasia
T cell disorder
classic triad:
Progressive cerebellar ataxia
Oculocutaneous telangiectasias
Recurrent sinopulmonary infections (immunodeficiency)
A new refugee with adenitis that grew S. aureus. You find out on history that he also had adenitis after BCG. What is the test to reveal the diagnosis?
infxn after vaccine - think T
T cell defect
- testing: lymphocytes (low), flow cytometry for t cells
4 year old with Staph aureus pneumonia, lung abscess, stomatitis, impetigo on the face and mouth ulcers. Which PID and how do you test
CGD
granulocyte disorder
oxidative burst / DHR / BHT
autoimmune polyglandular syndrome type 1
t cells attack endocrine glands
- parathyroid
- adrenals
- gonads
severe cutaneous candidiasis
is recurrent AOM in PCD or CF?
PCD
definitive management of SCID
preferably HLA matched sibling stem cell transplant
if no sibling, can use HLA matched unrelated donor
