Allergy and Immunology Flashcards
What are clinical findings of acute GVHD?
Within 3 months of transplant
Skin (rash), GI (anorexia, D&V), liver (transaminitis, hyperbili)
Prevent with immunosuppression (cyclosporine, tacrolimus), treat with steroids
What are clinical findings of chronic GVHD?
Occurs more then 3 months post transplant
Skin (malar rash, sica syndrome), MSK (arthritis, joint contractures), lung (bronchiolitis obliterans), liver (cholestasis, bile duct degeneration), eyes (dry eyes, conjunctivitis)
- An 18 month old boy has had 3 pneumonias, 2 episodes of OM and now presents with purulent nasal
discharge. On examination he has a tender 1x1.5cm cervical node with overlying redness. His mother
states that he had an episode of varicella a month ago that was fairly typical in course. Which of the
following investigations will most likely lead to the diagnosis:
Concept: findings of primary immune deficiency
c. Immunoglobulins
PID: recurrent sinopulmonary infections suspicious for innate issues (complement defect), adaptive immunity (B cell defect).
Ix: B cells: look at immunoglobulins and antibody titres
- complement (C3, C4, CH50)
ALSO, CVID and ataxia-telangiectasia both present with recurrent sinopulmonary infections and low immunoglobulins
- Which allergy can be treated with immunotherapy:
b) bee sting allergy
Allergies that respond to immunotherapy:
- seasonal or perennial allergic rhinoconjunctivitis
- asthma triggered by allergen exposures
- insect venom sensitivity
- IVIG can be used in all of the following EXCEPT:
c) nephrotic syndrome
Can be used in: ITP, bone marrow transplant (patients exposed to measles), KD, Guillain-Barre
- A child has received IVIG in the course of their treatment. How long should you wait before giving
them vaccines to ensure adequate response:
d. 11 mo
Varies between 3-11 months depending on product and dose used
- Which is true regarding RAST:
Concept: comparison of RAST to skin testing
d. false positives in children with hyper-IgE states
RAST = testing for allergen specific IgE (now more commonly called allergy specific IgE or sIgE test)
some facts: less sensitive than skin testing, not preferred method for food allergies (skin testing is), BUT not affected by corticosteroids or antihistamines, while skin testing is (neither are affected by montelukast)
13mo child with diaper rash and diarrhea with the introduction of new foods over the
past couple months. Which of the following is most consistent with this presentation:
c. carbohydrate intolerance is a common cause
- Sucrase-Isomaltase Deficiency- high amongst Canadian natives- when feeding milk and lactose- no symptoms- once exposed to sucrose and starches (juice, fruits,
crackers, other starches) develop diarrhea, diaper rash, FTT, abdominal distensionavoid
sucrose and maltose- Rx sacrosidase (Sucraid) - no role for RAST in diagnosis because this is only good for suspected IgE mediated CMPI
- 5 year old had a severe reaction to peanut at 1 year of age. He also has asthma. Now, allergist has
ordered an IgE level for peanut. Mom is wondering why. What do you tell them?
d. it prevents systemic reactions that could result from the skin test
Kid to have RAST for possible peanut allergy: 2 advantages over skin test; 1 disadvantage compared to
skin test.
advantages: ● Better safety ● Results are not influenced by skin disease or medications disadvantages: ● less sensitive
- Recurrent meningococcal meningitis. Most common immunodeficiency is:
a. C5 deficiency
Consider complement deficiency if:
o Recurrent angioedema
o Autoimmune disease (SLE, nephritis, HUS, partial lipdystrophy) - C1, C3, C4
o Recurrent pyogenic infections
o Disseminated meningococcal or gonococcal infection - C5-9
o 2 episodes of bacteremia - C2
o Meningitis with uncommon serotype (other than A, B or C)
- You suspect a 6 year old of having a T-cell defect. The best screen is:
c. Candida skin test
Screening tests for T cell defect: lymphocyte count, CXR for thymus size, delayed skin tests (candida, tetanus toxoid)
- Deficiency of which of the following may lead to anaphylaxis in a patient given IVIG:
a. IgA
44% have antibodies to IgA (which if they are IgE mediated can cause anaphylaxis to blood products including IVIG)
- In which condition is the IgE level normal:
b) immune thrombocytopenic purpura
What is the expected IgE level in Wiskott-Aldrich?
high
What is the expected IgE level in selective IgA deficiency?
low
What is the expected IgE level in Kawasaki?
high
- A 6 year old presents with eczema, decreased platelets and recurrent OM and
pneumonias. Increased IgA and IgE. Decreased IgG. Your diagnosis is:
a. Wiskott-Aldrich
It’s a TIE! (TCP, immunodeficiency, eczema)
- Low T cell percentages
- treat with IVIG, killed vaccines, BMT curative
Mnemonic: IgG&M low, IgA&E high - it’s a tie
- 3 year old with a history of fevers. Occur every 4 to 12 weeks for 1-4 days. Growing well. Treated for
numerous otitis and pharyngitis.
A) multiple viral infections
- A 15-year-old boy has had 5 episodes of documented pneumonia, 3 RML, 1 RLL, and 1 LLL.
What investigation would be most helpful:
a) immunoglobulins with IgG subclasses
X-linked agammaglobulinemia versus CVID: first have small or no tonsils and lymph nodes, second have normal tonsils and nodes
- What is true about chronic granulomatous disease:
b) suppurative lymphadenopathy is a characteristic feature
Normal number of neutrophils but abnormal function (can eat catalase producing bugs but not kill them)
- features include pneumonia, lymphadenitis, abscesses, onset in infancy
- infections with staph, gram negative enterics, candida, aspergillus
Dx: flow cytometry and genetic testing (used to use nitroblue tetrazolium)
- In chronic granulomatous disease, all of the following features are present EXCEPT:
e) hypogammaglobulinemia - no, can have hypergammaglobulinemia
- A 6mos male has several abscesses (S. aureus) now and in the past. He has also had recurrent
respiratory infections and Serratia UTI. Now has butt abscess. Which diagnosis is most likely?
c. CGD
Common bugs of CGD:
- staph aureus most common
- serratia marcescens
- B cepacia
- aspergillus
- candida albicans
- nocardia
- salmonella
- mycobacterium
- Which of the following is true in Wiskott-Aldrich Syndrome?
d) increased risk of malignancy
Which immune deficiencies are associated with increased risk of leukaemia and lymphoma?
Wiskott-Aldrich, SCID, CVID, X-linked lymphoproliferative syndrome - all are associated with defects in immune surveillance
- Which of the following is true of patients with X-linked agammaglobulinemia?
b. should not get live vaccines
All immunoglobulins are low; they have no circulating B cells
- Which lab abnormality is seen in Ataxia-telangiectasia? (which immunoglobulin is decreased?)
a. decreased IgA (selective absence of IgA in 50-80% of patients), IgE and IgG can also be low
- 18 mo M with knee arthritis, aspirate grew N. meningitidis. This is the same organism that grew in his
CSF when he had meningitis at 10 months. Which of the following tests is most likely to be abnormal in
this child?
b. C3,C4, total hemolytic complement
C3, C4 - assesses number
CH50 - assesses classical pathway function
AH50 - assesses alternate pathway function
- A 4 month old baby presents with eczema, recurrent pneumonias and absent thymus shadow on
CXR. What is the most likely diagnosis?
a) SCID
All SCIDs lack T cells, some also have no B or NK cells
- lack all Ig classes and subclasses
- extreme susceptibility to bacterial, viral and parasitic infections
- DO NOT give live vaccines
- What is true for X linked agammaglobulinemia?
a. respond to protein antigens (no they do not)
b. no live vaccines
c. at risk for PCP (rare)
d. risk of lymphoma, LIP (no lymph tissue)
e. risk of EBV associated diseases (EBV infect B cell thus immune)
b. no live vaccines
S. aureus. What finding would confirm your diagnosis?
a. absent radius
b. no LNs/tonsils
c. draining ears
d. hypoplastic patellae
c. draining ears
Wiskott-Aldrich
Patients with hyperIgE syndrome are classically infected with which bacteria:
● Recurrent severe staphylococcal abscesses of skin, lungs, other + elevated serum IgE
10 year old Lebanese girl with recurrent self limited fevers and abdominal pains. Her albumin is low, and her AST and ALT are slightly elevated (ie: 60-80 range). The remainder of investigations are negative (they don’t tell you what those investigations are!). What is the most likely diagnosis? a. Familial Mediterranean Fever b. SLE c. Cyclic Neutropenia
a. Familial Mediterranean Fever (more in keeping w/ abdo pain + fever)
- fever for 1-2 days every 1-2 months + serositis, arthritis, erysipeloid rash (over dorsum of foot)
o ESR, CRP, fibrinogen, serum AA (amyloid A) often increased
What are some diagnostic criteria for SLE?
SOAP BRAIN MD serositis (pleuritis, pericarditis) oral ulcers arthritis photosensitivity blood low (anemia, TCP, leukopenia) renal - protein loss ANA positive Immune markers (dsDNA) positive Neuro (psych, seizures) Malar or discoid rash
1.You are seeing a 14 month old boy with a history of severe atopic dermatitis and frequent infections.
On his CBC you find that he has a platelet count of 80.
What is the most likely diagnosis?
Wiskott Aldrich Syndrome
- After how many invasive infections would you be concerned about an immunodeficiency?
Nelson’s- 1 o r more systemic (sepsis, meningitis) bacterial infections; 2 or more serious or
documented bacterial infections in 1 year.
b.) List 4 investigations for work-up of a patient with suspected immunodeficiency
- CBC + Diff
- Immunoglobulins
- Vaccine Titres
- Flow cytometry
Note:
- normal ESR rules out chronic bacterial or fungal infection
- normal neuts rules out congenital and acquired neutropenias and leukocyte adhesion defects
- normal lymphs rules out severe T cell defect
- normal platelet size and count rules out Wiskott
6 week old baby with erythema and induration around his umbilical cord which is still firmly attached.
What underlying condition should you be suspicious of?
LAD I – (Leukocyte Adhesion defect type I)
- recurrent bacterial and fungal infections, despite lots of neutrophils
- note: more than 3 weeks is considered delayed separation of umbilical cord,but 10% of normal infants take >3 weeks
- diagnosis: flow cytometry
Name two organ systems and two organisms that are typically affected by granulocyte defects.
Skin (skin & soft tissue infections) and lungs (pneumonia)
Staphylococcus spp, Serratia marcescens , Klebsiella spp, other Gram negative organisms
(Granulocytes are the precursor to neutrophils, eosinophils & basophils)
Kid has had several infections. What other 4 findings would suggest immunodeficiency?
Failure to thrive
Family history of primary immune deficiency
Need for IV antibiotics to clear infections
Two or more months on antibiotics with little effect
Persistent thrush
Description of a child who is having multiple episodes of otitis media and pneumonia. Lab results given
are IgG 8(normal), IgM normal and IgA 0.01(decreased). What important piece of advice would you warn
this child about? (and what do they have?)
Selective IgA deficiency
Anaphylaxis to blood transfusions → Serum antibodies to IgA are reported in as many as 44%
of patients with selective IgA deficiency
- Which is true regarding allergic rhinitis:
a. indoor mould is not a trigger
b. long term follow up shows that symptoms persist into adulthood
c. these children go on to develop asthma
d. ingested substances are more significant than inhaled substances in perennial rhinitis
e. it always starts less than 5 years of age
b. long term follow up shows that symptoms persist into adulthood
o Rare if <1 year (need two seasons of exposure)
- The best therapy for perennial allergic rhinitis:
a) avoid exposure to allergens
b) intranasal corticosteroids
c) oral antihistamines
d) oral corticosteroids
e) sodium cromolyn
a) avoid exposure to allergens
Nasal steroids also very effective
- Boy with runny nose and itchy eyes in summertime. List 3 signs on physical exam that you’d see with this diagnosis.
b. ) Initial treatment x1
Allergic rhinitis
- allergic shiners
- nasal crease
- pale boggy nasal turbinates
Also:
allergic conjunctivitis
dry skin (xerosis)
keratosis pilaris
Tx: avoidance of trigger, antihistamines, inhaled steroids
Name 2 advantages of second generation anti-histamines
● Typically lipophobic – therefore less likely to have CNS effects
o i.e. less sedation, better school outcomes in children
● Quick onset of action (w/in 1 hr) and peak levels w/in 2-3 hrs
● Longer acting and less frequency
6 year old Mom concerned about chronic nasal congestions. What 4 things on history would suggest
allergic rhinitis? 3 Physical finding which support allergic rhinitis.
Hx: ● Seasonal appearance of symptoms
● Specific environmental triggers
● Positive family history - risk of allergic disease in a child approaches 50% when one parent is allergic and 66% when both parents are allergic.
● History of particular maneuvers: rubbing eyes, nose, allergic cluck
PE: ● Nasal crease ● Pale to purple/blue mucosa ● Thin, clear nasal secretions ● Cheilitis or dry lips → mouth breathing Allergic shiners
- A child is brought to the emergency room after being stung by a bee. He is wheezing
and moderately tachypneic and tachycardic. BP=100/70. First step in management:
a. 0.01mg/kg SC epinephrine
b. 0.01 mg/kg IV epinephrine
c. oxygen
d. methylprednisolone
e. Benadryl
c. oxygen
Definitely to also need to give epi but IM
O2 should be given to all patients with suspected anaphylaxis
- A child who is known to be allergic to peanuts presents to emergency after having eaten some 30
minutes ago. He is very itchy and has hives all over his body. His vitals including BP are stable and
there is no wheezing. Which of the following is correct?
a) IV epinephrine would be the preferred medication
b) Benadryl can be given IV, IM or PO
c) ventolin and Pulmicort should be administered
d) hydrocortisone does not prevent the late onset effects
e) desensitization therapy should be undertaken
b) Benadryl can be given IV, IM or PO
a possible anaphylactic reaction. Where will you give it:
a. SC in the abdomen
b. IM
c. SC in the thigh
d. IV
b. IM
- Child with signs of anaphylaxis after the transition to cow milk formula.
a) Most important medication in the immediate management and route?
b) When can the patient go home (i.e. how long does she need to be observed)?
c) List 4 preventative recommendations for the non acute management.
a) IM Epinephrine
b) More than 90% of biphasic responses occur within 4 hr, so patients should be observed
for at least 4 hr before being discharged from the ED.
c) 1. Allergen avoidance
2. Education of symptoms of anaphylaxis
3. Carrying epinephrine (an EpiPen)
4. Written emergency plan should be prepared ( www.foodallergy.org )
- Kid ate Chinese food at birthday party. Since then has had 2 weeks of angioedema, urticaria.
Rx? (and diagnosis?)
- Kid ate Chinese food at birthday party. Since then has had 2 weeks of angioedema, urticaria.
b. Antihistamine (second generation like cetirizine best option)
If H1 antihistamine does not achieve sufficient control, then can add H2 blocker (ranitidine)
Prednisone for severe angioedema or unresponsive to H1 and H2 blockers
acute urticaria (<6 weeks) - wheals or angioedema
Causes of acute urticaria?
● Acute < 6 weeks o Food o Meds o Insect Stings o Infection o Contact allergy o Transfusion Reaction
Causes of chronic urticaria?
● Chronic > 6 weeks o Idiopathic (2/3 of cases) o Physical (1/3 of cases) o AI (Thyroid, JIA, SLE, Celiac etc.) o Periodic fever syndromes o Neoplastic
Differential diagnosis of urticaria? (important stuff not to miss)
● KEY DDX: Erythema Multiforme (targetoid, central necrosis or vesicles, duration> 7 d on palms
and soles ++, no dermographism, MM can be involved)
● Key DDX: utrticaria pigmentosa (type of mastocytosis; reddish brown macules that may wheal
when stroked)
- Child has recurrent episodes of face and ear swelling. Father has a similar history. This has stopped
in the past four weeks as he has stopped drinking milk and eating cheese. He still eats ice cream. The
rash is not itchy. What is the diagnosis?
a) acute intermittent urticarial (just means < 6 weeks and NYD)
b) chronic urticarial (just means > 6 weeks)
c) cow’s milk protein allergy ( but has ice cream)
d) C1 esterase deficiency
d) C1 esterase deficiency (aka hereditary angioedema)
C1 esterase inhibits the complement system to prevent spontaneous activation -without it get complement activation and leaky blood vessels causing edema
Tx: replace C1 esterase
- Which is true regarding penicillin anaphylaxis
a. it is mediated by IgG against a major determinant
b. it is mediated by IgG against a minor determinant
c. it is mediated by IgE against a minor determinant
d. it is mediated by IgE against a major determinant
e. it is mediated by IgM against a major determinant
d. it is mediated by IgE against a major determinant
- 13 month old with diarrhea and diaper rash what is cause?
a. cow milk protein allergy
b. carbohydrate intolerance
c. immunodeficiency
b. carbohydrate intolerance
Investigations for carbohydrate malabsorption (12 month old with diarrhea and diaper rash)
● TESTING
o Maldigested carb emptied into colon = osmotic effect
o + colonic bacteria ferment these carb= gas + acids
o Testing therefore = stool pH < 5.5, hydrogen breath test (+)
- Picture of a 7 year old boy’s thigh, linear vesicles with some excoriation. He comes to your office, in
July, with a rash on his left thigh, It is itchy and has seemed to spread where he scratches.
a)What is your diagnosis
b)what is your treatment
● Washing the skin and other items that may have come in contact with the plant
● If patient develops skin lesions, systemic antihistamines are usually needed.
● Mild to moderate strength (class 7 to 4) topical steroids are appropriate.
● Topical pramoxine (an antihistamine) is safe and can be used over large areas of the body 2–3
times a day
● If lesions are more extensive, systemic steroid therapy for 2 weeks at a beginning dose of
0.5–1.0 mg/kg, followed by a rapid taper over the subsequent 2 weeks.
- Neutropenic child with central line site red.
Which antibiotics?
● Anti-pseudomonal beta-lactam: cefepime, ceftazidime, meropenem or pip-tazo
● Anti staph: vancomycin
A mother has come in with her 12 month old, and is concerned by the “number of shots” that is getting
today. She has read in the paper about how is it bad to expose a child to a large number of “antigens” all
at once, and is worried about overwhelming his immune system. What advice can you give to help
alleviate this motherʼs worries? (2 points)
● Children are often exposed to more antigens from routine daily activities as compared to the routine vaccine schedule
● Few are aware of Canada’s robust vaccine safety system or that vaccines are held to a higher
safety standard than drugs.
What are THREE indications for giving the conjugated quadrivalent vaccine for meningococcus?
Risk increased because of underlying medical conditions
● Asplenia or functional asplenia, including those with sickle cell anemia
● Properdin, factor D or complement deficiency (including those with acquired complement
deficiency from eculizumab (Soliris); primary antibody deficiency)
● HIV
Risk increased because of the potential for exposure
● Travellers to endemic areas (currently, travellers to sub-Saharan Africa and Hajj pilgrims)
● Close contacts of a case of invasive meningococcal disease
