Allergy and immunology

Question 1

10 red flags of immunodeficiency

Answer 1

2 or more ear infections in a year
2 or more sinus infections in a year (in absence of allergy)
1 pneumonia per year for more than 1 year
chronic diarrhoea with weight loss
Recurrent viral infections
Recurrent need for IV ABx
Recurrent deep abscess of tissue or organs
recurrent thrush or fungal infection
Infection with normally harmless TB like bacteria
Family history of primary immunodeficiency

Question 2

Secondary causes of immunodeficiency

Answer 2

DM
HIV
Cirrhosis
Nephrotic syndrome
Autoimmune disease
malignancy
Asplenia
Immunomodulatory drugs
structural (obstructive tumors, strictures
burns
dermatitis

Question 3

Indications for irradiated RBC’s

Answer 3

Bone marrow Transplant
Acquired or congenital immunodeficiency
blood components donated by first or second degree relatives

Question 4

indications for leukoreduced RBC’s

Answer 4

CMV seronegative at risk patients (AIDS etc)
Chronically transfused patients
potential transplant recipients
previous febrile nonhemolytic transfusion reaction

Question 5

indications for washed RBC’s

Answer 5

IgA deficiency
complement dependent autoimmune hemolytic anemia
continued allergic reaction to red cell transfusion despite antihistamine treatment.

Question 6

diagnosing combined variable immunodeficiency

Answer 6

low IgG + IgA or IgM
poor response to vaccinations
other causes of immunodeficiency ruled out

Question 7

treatment for combined variable immunodeficiency

Answer 7

IVIG or SubC IG

Question 8

common triggers for acute urticaria

Answer 8

abs, NSAIDs, Insects, food
ACUTE LASTS LESS THAN 6 Weeks

Question 9

Red flags for urticaria

Answer 9

lasts over 48 hours
heals with a bruise or scar
Burning or stinging pain
Red flags should raise suspicion of autoimmune or systemic disease

Question 10

typical urticarial symptoms

Answer 10

lasts less than 6 hours
Heals without skin changes such as bruising
pruritus

Question 11

symptoms of chronic spontaneous urticaria

Answer 11

lasts over 6 weeks
no obvious trigger

Question 12

workup for chronic spontaneous urticaria

Answer 12

CBC + Diff
ESR/CRP
+/- autoimmune panel
+/- Tryptase if systemic Sx (mastocytosis)
+/- biopsy (vasculitic urticaria

Question 13

Acute treatment angioedema

Answer 13

STOP offering agent/ trigger
Oropharyngeal oedema or Anaphylaxis - EPI 1:1000 IM (0.5ml)
H1 bloker: diphenhydramine 25-50mg IV
H2 blocker: Ranitidine 50mg IV
Steroids: methylprednisolone 60-80mg IV
ACEi Angioedema: Icatibant
Known HAE: just need Icatibant

Question 14

Differential diagnosis for angioedema (No pruritus/urticaria)

Answer 14

Hereditary Angioedema/ C1 esterase inhibitor deficiency
Lymphoproliferative or autoimmune disease
ACEi angiodema
Idiopathic angioedema
Trigger related e.g. food/drugs/insect bites

Question 15

Complement levels in HAE type 1

Answer 15

C1i Level: Low
C1 inhibitor function: Low
C4: Low

Question 16

Complement levels in HAE type 2

Answer 16

C1i Level: normal/high
C1 inhibitor function: low
C4: low

Question 17

Complement levels in HAE type 3

Answer 17

C1i Level: Normal
C1 inhibitor function: Normal
C4:Normal

Question 18

Complement levels in acquired angioedema

Answer 18

C1i Level: Low
C1 inhibitor function: Low
C4: Low

Question 19

complement level in ACEi angioedema

Answer 19

C1i Level: normal
C1 inhibitor function: normal
C4: normal

Question 20

Complement levels in idiopathic angioedema

Answer 20

C1i Level: normal
C1 inhibitor function: normal
C4: normal

Question 21

Treatment of anaphylaxis

Answer 21

IM Epi - 0.01mg/kg MAX 0.5mg (0.5ml)IM 1:1000 q5-15mins
Consider IV after several doses on IM, profound hypotension or obese patients (0.05-0.1mg IV over 5min then 2-10 mag/min titrated to BP)
Ranitidine 50mg IV q8h/ PRN
Diphenhydramine 25-50mg IV q4-6h/PRN
Methylprednisolone 125mg IV q6h/PRN
Glucagon if on beta blockers
salbutamol for bronchospasm
Vasopressor for persistent hypotension
patient should be observed minimum 4-6 hours

Question 22

discharge planning for Anaphylaxis

Answer 22

Prescribe Epinephrine autoinjector 0.3mg IM PRN
Anaphylaxis action plan
Patient/Caregiver education
Medicalert bracelet
Referral to allergist/ immunologist

Question 23

Anaphylaxis diagnostic criteria

Answer 23

possible allergen +skin/mucosa involvement + Resp compromise or HoTN/EOF
OR
Likely allergen + 2 of Skin/mucosa, Resp compromise, HoTN/EOF persistent GI sx
OR
Known Allergen + HoTN

Question 24

IgE mediated Penicillin allergy Sx

Answer 24

Pruritus
Urticaria
Angioedema

Question 25

Non-IgE mediated Penicillin Allergy Sx

Answer 25

SJS-TENS (blistering, desquamation, conjunctivitis)
DRESS (eosinophilia, fever, end organ involvement)
Serum Sickness (arthritis, Fever)

Question 26

Management of IgE mediated Penicillin reaction

Answer 26

Allergy referral for skin test with oral challenge (90% of patient will test negative)
Drug desensitization if positive skin test (safe in pregnancy) or required acutely. this gives TEMPORARY induction of tolerance and does not rule out allergy.

Question 27

Diagnostic criteria for allergic bronchopulmonary aspergillosis

Answer 27

Predisposing condition, asthma or CF
Elevated IgE AND elevated AF specific IgE OR immediate cutaneous reactivity to AF
2/3 of: radiographic pulmonary opacities (central bronchiectasis), eosinophilia, serum Abs to AF or elevated AF specific IgG

Question 28

treatment for ABPA

Answer 28

high dose oral glucocorticoid
Antifungal (Itraconazole or voriconazole) are also used.