Allergy/Immunology Flashcards
1
Q
Angioedema - classification by mechanism
A
+Urticaria –> activation of mast cells –> IgE mediated, direct mast cell activation, or non-IgE mediated
-Urticaria –> unknown or generation of bradykinin –> hereditary or acquired
2
Q
Diagnosis to r/o for delayed umbilical cord seperation
A
Leukocyte adhesion defect (type 1)
3
Q
Common bugs and presentations suggestive of phagocytic (neut) defects
A
Bugs = catalase positive organisms (aspergillus, S. aureus) Prez = umbilical separation delay, poor wound healing, severe gingivitis, SSTI, solid organ infection
4
Q
Dx - potentially life threatening, non-pruritic swelling (with no urticaria), and recurrent abdominal pain
A
Hereditary C1 inhibitor deficiency = recurrent angioedema to face/body, GI tract, and airway
5
Q
Common bugs and presentation for complement defect immunodeficiency
A
- Bugs = encapsulated organisms (Neisseria*)
- Prez = rheum disorders/autoimmune, increased susceptibility to infection, angioedema
6
Q
Mneumonic for hypersensitivity reactions
A
ACID = acute, cytotoxic, immune complex mediated, delayed
7
Q
4 types of hypersensitivity with x1 example
A
- Type 1: IgE, anaphylaxis
- Type 2: IgG/IgM cytotoxic, hemolytic anemia
- Type 3: Immune complex mediated, serum sickness/SLE
- Type 4: T-cell, SJS
8
Q
When (timing wise) is the best time to swab an asymptomatic neonate following C/S for a mother with HSV lesions?
A
> 24 hours from birth
9
Q
Spectrum of presentations for a parvovirus infection
A
- Asymptomatic
- Erythema infectiosum (5th disease, slapped cheek)
- Transient aplastic crisis with hemolytic anemia
- Chronic anemia in child with immunodeficiency
- Hydrops fetalis
- Arthritis/arthralgia
10
Q
GAS pharyngitis - tx of choice, duration, when child can go back to daycare?
A
10 days of penicillin or amox
-Go back after 24 hours of Abx
11
Q
GAS pharyngitis - time window when can treat with Abx
A
For 9 days since onset of symptoms
12
Q
GAS pharyngitis - why treat with Abx
A
- Shorten illness course
- Prevent ARF
- Prevent suppurative complications
- Decrease spread of infection
13
Q
Scarlet fever - what is rash caused by and how does the rash present?
A
- Caused by strep pyrogenic exotoxin
- Begins on neck, face, and upper trunk then spreads to rest of body within 1-2 days
- Palm/sole sparing
- Sandpaper texture, erythematous, blanchable papules
- Pastia lines =erythema in skin folds
- Desquamation in 5-7 days
14
Q
Indications for tonsillectomy
A
- OSA secondary to adenotonsillar hypertrophy
- Recurrent throat infection: >7 past year, >5 last 2 years, >3 last 3 years
- History of peritonsillar abscess
- Multiple Abx allergy/intolerance
- PFAPA
15
Q
Basic screen of labs for immunodeficiency (x7)
A
- CBC
- Immunoglobulins
- Complement: CH50, C3, C4
- Vaccine titres
- Infectious w/u
- Immunodeficiency panel
- CXR
16
Q
x9 red flags for immunodeficiency
A
- 4 or more AOM in 1 year
- 2 or more serious PNA in 1 year
- 2 or more serious sinus infection in 1 year
- 2 or more deep seated infections
- Recurrent deep skin or organ abscesses
- Recurrent thrush when >1 year of age
- Required IV Abx to clear infections +/- >2 months total of Abx with little effect
- FTT
- Family history
17
Q
Clinical presentation for IgE Syndrome
A
- Coarse facial features
- Atypical eczema
- Recurrent infections - S.aureus, PNA with pneumatoceles
- Delayed tooth exfoliation
18
Q
Common bugs for B-cell deficiency (x6)
A
- Gram pos + neg bacteria, encapsulated
- Giardia
- Cryptosporidium
- Mycoplasma
- Enterovirus
- Campylobacter
19
Q
Classic presentation for B-cell deficiency + other symptoms
A
- Sinopulmonary infections
- Bronchiectasis unexplained
- Other: malabsorption, diarrhea, ileitis/colitis, arthritis
20
Q
Bugs + presentation of predominant T-cell disorder
A
- Bugs = viruses, fungal
- Presentation = oral candidiasis, opportunistic infections, other (GVHD, FTT, skin rash, sparse hair)
21
Q
x2 examples of Ab-deficiencies (humoral or B-cell)
A
- Common variable immunodeficiency
- X-linked agammaglobulinemia
22
Q
x5 examples of combined deficiencies
A
- SCID
- Wiskott-Aldrich Syndrome
- 22q11 deletion syndrome
- Hyper IgM syndrome
- Ataxia telangiectasis
23
Q
x2 examples of phagocytic defects
A
- Chronic granulomatous disease
- Leukocyte adhesion defect
24
Q
Secondary causes for recurrent infections
A
- Meds: steroids, chemo, anti-epileptics
- Infection: HIV, TB, measles, influenza, herpes group
- Structural: anatomic, impaired membrane integrity, immotile cilia, CF, indwelling catheter
- Malignancy: lymphoma, leukemia, solid tumors, myeloma
- Other: DM, renal insufficiency, PLE, malnutrition, lymphangiectasia, asplenia
25
Work-up for humoral assessment
- Number: lymphocyte subsets (flow cytometry) + immunoglobulins (check albumin to screen for secondary loss)
- Function: Vaccine titres, isohemagglutinins (IgM Ab to blood group A/B)
26
Work-up for cellular assessment
- Number: lymphocyte total count and subsets
| - Function: specialized testing
27
Work-up for phagocytic assessment
- Number: neutrophil number
| - Function: adhesion markers (CD11+CD18 for leukocyte adhesion defect), neutrophil oxidative burst index (for CGD)
28
Work-up for complement assessment
- Number: C1 esterase inhibitor levels
| - Function: total hemolytic complement (CH50), alternate pathway (AH50), C1 esterase inhibitor function
29
X-linked agammaglobinemia: what is it and when does it present
- Caused by mutations in the tyrosine kinase that is important for B cell maturation
- Absent B lymphocytes in peripheral blood = no Ig production
- Presents 6-24 months when maternal IgG disappears
30
What to look for on exam in X-linked agammaglobinemia?
No tonsils or LNs
31
What will you find on Ix for X-linked agammaglobinemia?
- No B cells
- No immunoglobulins
- No Abs to vaccines
32
Therapy for X-linked agammaglobinemia?
IgG replacement for life
33
What are children with X-linked agammaglobinemia at risk for?
Bronchiectasis
34
What are the x3 classic features of Common Variable Immunodeficiency?
- Recurrent sinopulmonary infections
- Autoimmunity
- Malignancy
35
Difference on exam between Common Variable Immunodeficiency and XLA?
Presence of lymphatic tissue in CVID
36
What do labs show in Common Variable Immunodeficiency?
- Number: Decreased serum IgG, variable B cells
| - Function: absent/reduced Ab vaccines, low isohemagglutinins
37
What is SCID?
Profoundly defective T + B cell function
38
When does SCID present?
2-6 months old
39
Are LN's and tonsils present on exam in SCID?
No
40
What would Ix show in SCID?
- CXR: no thymus
- Lymphopenia with low/absent T cell function
- Absent Ab to vaccines
41
Mgmt for SCID
- New immune system = HSCT, gene therapy
- Prevent/tx infections = Abx, PJP proph, protective isolation, immunoglobulin replacement tx, blood products (CMV neg + irradiated), avoid live vaccines
42
Triad for Wiskott-Aldrich Syndrome
- Thrombocytopenia
- Eczema
- Recurrent infections
43
What would investigations show for Wiskott-Aldrich Syndrome
- Number: thrombocytopenia (small), eosinophilia, +/- lymphopenia, variable IgG, low IgM, high IgA/IgE
- Function: poor Ab response to some vaccines, decreased T cell function
44
Management for Wiskott-Aldrich Syndrome
- Immunoglobulin replacement therapy
- PJP prophylaxis
- HSCT
- Monitor for autoimmune/malignancy
45
What autoimmune conditions (x3) are associated with Wiskott-Aldrich Syndrome?
- Hemolytic anemia
- Vasculitis
- IBD
46
What malignancies (x2) are associated with Wiskott-Aldrich Syndrome?
- B cell lymphoma
| - Leukemia
47
What immunodeficiency must you rule out in a patient with PJP?
SCID
48
What to think of with ataxia + lymphoma?
Ataxia telangiectasia
49
Where to look on exam for telangiectasia in AT?
Conjunctiva, ears, face
50
Mode of inheritance for ataxia telangiectasia
Autosomal recessive
51
What immunodeficiency do you need to avoid ionizing radiation?
Ataxia telangiectasia
52
What malignancy are patients with Ataxia telangiectasia most at risk for?
Lymphoma
53
What x1 lab is specific for Ataxia telangiectasia?
Increased AFP
54
What immunodeficiency has progressive neurodegeneration?
Ataxia telangiectasia
55
What part of the immune system is impacted in Ataxia telangiectasia?
T-cell (cellular)
56
What organisms to think of for Chronic Granulomatous Disease?
Catalase positive = S. aureus, aspergillus, serratia, burkholderia, salmonella
57
What autoimmune condition is associated with Chronic Granulomatous Disease?
IBD
58
What would investigations show for Chronic Granulomatous Disease?
- Normal number of neutrophils
| - Abnormal function on oxidative burst
59
Features of Hyper IgE syhndrome
- Recurrent abscesses in skin + lungs from S. aureus
- Mucocutaneous candidiasis
- Eczema
- Delayed shedding of primary teeth
- Bone #, scoliosis, joint laxity
60
What would you find on labs for hereditary angioedema?
-Deficiency in C1 inhibitor
61
Mode of inheritance in hereditary angioedema
Autosomal dominant
62
What is the more likely cause (rather than a B-lactam allergy) for maculopapular exanthems in children?
Viral infection
63
Type 1 immune reaction
- IgE mediated
| - <2 hours to symptoms
64
Type 2 immune reaction
- Cytotoxic
- 10h to a week to symptoms
- Anemia, thrombocytopenia
65
Type 3 immune reaction
- Immune complex
- 1-3 weeks to symptoms
- Serum sickness-like reaction
66
Type 4 immune reaction
- T-cell mediated
- 2-14 days
- SJS, DRESS
67
What is the gold standard for ruling out a beta-lactam IgE-mediated allergy - when thought to be unlikely
Provocative drug challenge
68
Serratia - what immunodeficiency do you think of?
CGD
69
Most common use of immunotherapy?
Bee sting allergy
70
Match C3 deficiency and C5 deficiency with (a) early vs late complement component and (b) associated with autoimmune vs meningococcal
C3 - early, autoimmune
| C5 - late, meningococcal
71
What immunoglobulin deficiency has an increased risk of anaphylaxis with IVIG?
IgA
72
Most common food allergens
- Wheat
- Fish
- Shellfish
- Peanuts
- Tree nuts
- Sesame
- Soy
- Milk
- Egg
73
x2 ways to test allergies
- Skin prick testing
| - IgE blood test = RAST
74
What is the benefit of RAST vs skin prick testing?
Can stay on medications like montelukast
75
Tx for serum sickness like reaction
- Stop offending agent
| - PO steroids
76
Presentation of serum sickness like reaction
- Rash
- Arthralgia
- Fever
- Edema
- LAD
- No mucous membrane involvement
77
What are the x2 indications for allergy testing and possible immunotherapy for insect venom reaction/allergy?
- If airway involvement
- If anaphylaxis
-Otherwise, do not refer for urticaria or localized reaction
78
What is the most effective use for immunotherapy in setting of allergies?
Bee sting allergy
79
Most important aspects of FPIES management
- IV fluid resuscitation
- Ondansetron
- Strict avoidance
80
x2 main types of mastocytosis
- Cutaneous
| - Systemic
81
Derm sign for cutaneous mastocytosis
Darier's sign
82
Lab finding in systemic mastocytosis
Elevated serum tryptase
83
Physical exam findings of allergic rhinitis
- Allergic shiners
- Dennie-Morgan lines
- Transverse nasal crease + allergic salute
- Allergic faces = high-arched palate, open, dental malocclusion
84
What medications to avoid with hereditary angioedema?
No OCP or ACEi's
85
What test to do for hereditary angioedema?
C1 esterase inhibitor levels + function
86
What is characteristic of a rituximab specific serum sickness reaction?
Palpable purpura along lateral aspect of feet
87
Serum sickness management
- Remove inciting agent
- Supportive care
- Antihistamines
- NSAIDs
- Analgesics
- If severe = steroids
88
What may you see on labs in serum sickness?
- Thrombocytopenia
- Proteinuria
- Elevated CRP/ESR
- Decreased C3/C4
89
What PID do you think of with serratia?
CGD
90
What PID do you think of with N.meng?
Complement
91
What is the dx = hilar lymph nodes, eosinophilia, elevated Ca, elevated ALP?
Sarcoidosis
92
What is the component that is affected in penicillin allergy?
Minor component
93
What does a candida skin test do?
Test T-cell function
94
What organ does chronic GVHD not affect (entirely...may be some unhappiness but no dysfunction)? ...oh RC questions
Liver
