Allergy Flashcards
List 10 red flags of immunodeficiency
- ≥2 new ear infections within 1 year
- ≥ 2 new sinus infections within 1 year in the absence of allergy
- One PNA per year for more than 1 year
- Chronic diarrhea with weight loss
- Recurrent viral infections (colds, herpes, warts, condyloma)
- Recurrent need for IV ABx to clear infections
- Recurrent deep abscesses of the skin or internal organs
- Persistent thrush or fungal infections on skin or elsewhere
- Infection with normally harmless TB-like bacteria
- FMHx of PID
What should you first rule out before suspecting a PID?
- R/O secondary causes of immunodeficiency
- DM, HIV, Cirrhosis, Nephrotic syndrome, Autoimmune diseases, Malignancy, splenectomy/asplenia, immunomodulatory drugs
- Structural issues
- Obstructive tumors
- urethral strictures
- Dermatitis
- Burns
What types of infection are associated with what type of primary immunodeficiency>
What investigations should be sent when suspecting a B-Cell deficiency?
- Lymphocyte count
- Lymphocyte subsets
- Immunoglobulins
- Vaccination titers
What investigations should be sent when suspecting a T-Cell deficiency?
- Lymphocyte count
- Lymphocyte subsets
What investigations should be sent when suspecting a Neutrophil deficiency?
- Neutrophil count
- Chronic granulomatous disease assay
What investigations should be sent when suspecting a Complement deficiency?
- CD3
- CD4
- CH50
What is the most common symptomatic PID in adults?
CVID
What are the symptoms of CVID
Recurrent sinopulmonary infections
How is CVID diagnosed?
Low IgG+IgA orr Low IgM + poor response to vaccination
Other immunodeficiency causes have to be ruled out (i.e. CLL)
How is CVID treated?
IVIG or SCIG
What are the common antigens/triggers for acute urticaria
- ABx (PNC, Sulfa)
- NSAIDS
- insects
- food (in adults=shelfish)
How long does acute urticaria lasts?
<6 weeks
How should acute urticaria be worked up?
Allergy referral for skin testing
What is the first line treatment for acute urticaria?
- Stop med/avoid trigger if ID
- Anti-histamines
Compare the typical symptoms of urticaria to the red flags. What do red flags raise the suspicion for?
What are the clinical manifestations of chronic spontaneous urticaria
- >6 weeks
- Most days of the week
- Spontaneous with no clear trigger
How should CSU be worked-up?
- CBC, CRP/ESR
- Workup of other causes of chronic urticaria as directed by clinical picture
- AI workup: ANA, ds-DNA, RF
- Serum tryptase if systemic symptoms to R/O mastocytosis
- Bx if concerns for urticarial vasculitis
How should CSU be treated?
- 1st line: Daily non-sedating antihistamines
- 2nd line: Increase dose of antihistamines to 4x usual dose
- 3rd line: Omalizumab
What is physical chronic urticaria
Urticaria triggered by pressure, heat, cold
What is the likely pathophysiological phenomenon behind angioedema if it is accompanied by pruritus and urticaria
Mast cell mediated
What is the likely pathophysiological phenomenon behind angioedema if it is not accompanied by pruritus and urticaria
Mast cell or bradykinin mediated
What is the differential for bradykinin mediated angioedema
- Idiopathic angioedema
- HAE
- AAE
- ACE inhibitor mediated
- idiopathic angioedema
How is idiopathic angioedema treated?
- Rare episodes: Pred+ antihistamines at first sign of Sx
- Frequent episodes: Daily antihistamines
- Epinephrine auto-injector
How should HAE be managed?
Prophylactic C1 esterase inhibitor
How is angiooedema treated in the acute setting
- Stop offending agent/trigger
- H1-Blocker: Gravol 25-50 IV
- H2 blocker: Ranitidine 50 IV
- Steroids: Methylpred 60-80 IV
- COncerns for anaphylaxis or oropharyngeal angioedema: Give EPI
- If 2/2 to ACE: give Icatibant
- Known HAE: Skip above Tx and give C1 esterase inhibitor, Icatibant
What are the expected levels of C1 inhibitor levels, function and C4 in:
- HAE 1
- HAE 2
- HAE 3
- AAE
- ACE inh.
- Idiopathic
Give the diagnostic criteria for anaphylaxis?
What is the acute treatment of anaphylaxis?
- ABCs/MOIF
- STOP DRUG/REMOVE TRIGGER
- Epinephrine IM or IV
List adjunctive medications that can be used in Anaphylaxis
- H1 Blockers
- H2 blockers
- Steroids: Methylpred 125
- Glucagon for patients on BB
- Salbutamol if bronchoconstriction
- Vasopressors for persistent hypotension
*Observe until Sx improve, min 4-6hrs
What is the discharge plan for patients after anaphylaxis
- Epipen PRN
- Anaphylaxis action plan
- Patient/caregiver education
- Medicalert bracelet
- Referal to allergist-immunologist
What are the types of allergies to PNC
- IgE mediated
- SJS-TENS
- DRESS
- Serum sickness
How should PNC allergy be managed in the long term
- Allergy referral for skin testing +/- oral challenge
- 90% will test negative
- if + avoid PNC, high likelihood of reacting to 1st gen cephalosporins
- Drug desensitization
- TEMPORARY induction of tolerance. Does not R?O allergy
- Only for IgE mediated reactions
What is the safest beta lactam in patients with a PNC allergy
Azetronam
