Allergy and immunology Flashcards
10 red flags of immunodeficiency
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
Secondary causes of immunodeficiency
DM
HIV
Cirrhosis
Nephrotic syndrome
Autoimmune disease
malignancy
Asplenia
Immunomodulatory drugs
structural (obstructive tumors, strictures
burns
dermatitis
Indications for irradiated RBC’s
Bone marrow Transplant
Acquired or congenital immunodeficiency
blood components donated by first or second degree relatives
indications for leukoreduced RBC’s
CMV seronegative at risk patients (AIDS etc)
Chronically transfused patients
potential transplant recipients
previous febrile nonhemolytic transfusion reaction
indications for washed RBC’s
IgA deficiency
complement dependent autoimmune hemolytic anemia
continued allergic reaction to red cell transfusion despite antihistamine treatment.
diagnosing combined variable immunodeficiency
low IgG + IgA or IgM
poor response to vaccinations
other causes of immunodeficiency ruled out
treatment for combined variable immunodeficiency
IVIG or SubC IG
common triggers for acute urticaria
abs, NSAIDs, Insects, food
ACUTE LASTS LESS THAN 6 Weeks
Red flags for urticaria
lasts over 48 hours
heals with a bruise or scar
Burning or stinging pain
Red flags should raise suspicion of autoimmune or systemic disease
typical urticarial symptoms
lasts less than 6 hours
Heals without skin changes such as bruising
pruritus
symptoms of chronic spontaneous urticaria
lasts over 6 weeks
no obvious trigger
workup for chronic spontaneous urticaria
CBC + Diff
ESR/CRP
+/- autoimmune panel
+/- Tryptase if systemic Sx (mastocytosis)
+/- biopsy (vasculitic urticaria
Acute treatment angioedema
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
Differential diagnosis for angioedema (No pruritus/urticaria)
Hereditary Angioedema/ C1 esterase inhibitor deficiency
Lymphoproliferative or autoimmune disease
ACEi angiodema
Idiopathic angioedema
Trigger related e.g. food/drugs/insect bites
Complement levels in HAE type 1
C1i Level: Low
C1 inhibitor function: Low
C4: Low
Complement levels in HAE type 2
C1i Level: normal/high
C1 inhibitor function: low
C4: low
Complement levels in HAE type 3
C1i Level: Normal
C1 inhibitor function: Normal
C4:Normal
Complement levels in acquired angioedema
C1i Level: Low
C1 inhibitor function: Low
C4: Low
complement level in ACEi angioedema
C1i Level: normal
C1 inhibitor function: normal
C4: normal
Complement levels in idiopathic angioedema
C1i Level: normal
C1 inhibitor function: normal
C4: normal
Treatment of anaphylaxis
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
discharge planning for Anaphylaxis
Prescribe Epinephrine autoinjector 0.3mg IM PRN
Anaphylaxis action plan
Patient/Caregiver education
Medicalert bracelet
Referral to allergist/ immunologist
Anaphylaxis diagnostic criteria
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
IgE mediated Penicillin allergy Sx
Pruritus
Urticaria
Angioedema
Non-IgE mediated Penicillin Allergy Sx
SJS-TENS (blistering, desquamation, conjunctivitis)
DRESS (eosinophilia, fever, end organ involvement)
Serum Sickness (arthritis, Fever)
Management of IgE mediated Penicillin reaction
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.
Diagnostic criteria for allergic bronchopulmonary aspergillosis
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
treatment for ABPA
high dose oral glucocorticoid
Antifungal (Itraconazole or voriconazole) are also used.
