Allergy

Question 1

Types of allergy

Answer 1

Type 1 = IgE mediated hypersensitivity (allergy + anaphylaxis)
Type 2 = cytotoxic (anemia, thrombocytopenia)
Type 3 = immune complex (fever, urticaria, vasculitis, arthritis)
Type 4 = T cell mediated (maculopapular rash, SJS)

Question 2

Management of mild intermittent sx

Answer 2

Mild intermittent sx - oral antihistamines or intranasal antihistamines + allergy avoidance. 2nd line - combine therapies, intranasal corticosteroids

Question 3

When to prescribe epi pens

Answer 3

Epipens for: anaphylaxis hx, rapid onset systemic allergic reaction (GI, resp, cardiac sx), diffuse hives to food or insect stings, rapid onset reaction to high risk foods (peanut, tree nuts, fish, shellfish

Question 4

Management of Persistent mod to severe sx

Answer 4

intranasal corticosteroids + oral antihistamines + adjuncts (intranasal ipratropium, oral/ nasal decongestants, oral corticosteroids, intranasal saline irrigation). 2nd line: SL or SC immunotherapy

Question 5

Management of Mild persistent or moderate intermittent sx

Answer 5

• oral antihistamines + intranasal antihistamines + intranasal corticosteroids w/ nasal rinses or decongestants (beware rebound rhinitis). 2nd line: SL or SC immunotherapy

Question 6

Types of allergic rhinitis

Answer 6

Seasonal Rhinitis
Perennial Rhinitis
Occupational Rhinitis

Question 7

Types of rhinitis

Answer 7

Allergic (seasonal, perennial, occupational)
Infectious Rhinitis (viral, bacterial)
Irritant Rhinitis (chemical, exposures)
Drug Induced Rhinitis (Ace Inhibitors, ASA, NSAIDs, Beta Blockers, nasal decongestants)
Exercise Induced Rhinitis
Emotional Rhinitis
Gustatory Rhinitis
Hormone Induced Rhinitis (pregnancy, OCPs, hypothyroidism)
Vasomotor Rhinitis (temperature changes, humidity, age related)
Reflux Induced Rhinitis
Inflammatory Rhinitis (sarcoidosis, SLE, Wegener’s, Sjogren’s, granulomatous disease)
Structural Rhinitis (nasal polyps, deviated septum, foreign body, atresia, tumors, masses)

Question 8

Ix for rhinitis

Answer 8

IgE or skin prick testing

Question 9

Management of allergic rhinitis - intermittent, persistent and refractory sx

Answer 9

Intermittent sx: oral antihistamine, IN antihistamine, IN corticosteroids
Persistent sx: IN corticosteroids, IN antihistamine, oral antihistamine
Intranasal antihistamine (max 4w, risk of rebound)
Refractory: ant rhinorrhea = IN anticholinergic or oral steroids

Question 10

Sx of anaphylaxis

Answer 10

urticaria, angioedema, dyspnea, syncope, diarrhea, abdo cramps, flushing, airway edema, N/V, hypotension, itch, rhinitis

Question 11

What to include in counselling when prescribing epi pen

Answer 11

Self administration of epi pen - no contraindications! Show and then have pt show you how to use
Storage of epi pen
Return for immediate assessment if sx develop or if epi pen used
Anaphylaxis Emergency Plan from Health Canada website
If allergy to med or if pt had a previous major reaction, get MedicAlert bracelet
If pt is child with anaphylaxis to food, prescribe 4x epipens for car, house, school and daycare + ensure education of parents, teachers and caretakers of sx of anaphylaxis + when to use epi pen

How to use epipen:
Hold for 5s
Apply pressure to activate
Transport to hospital

Question 12

Anaphylaxis criteria

Answer 12

If no known exposure to allergen, but rapid onset skin or mucosal sx AS WELL AS resp or cardiovascular compromise = anaphylaxis
If exposed to allergen, 2 affected systems required (gastro, skin, resp, CV) = anaphylaxis
If hypotension after exposed to known allergen = anaphylaxis

Question 13

Management of anaphylaxis

Answer 13

Have poster for treatment of anaphylaxis in ED
Remove exposure to trigger
ABCs, examine skin and get body weight
Call for help
Adults: 0.3-0.5mg IM lateral thigh every 5-15 mins
Children: 0.1mg/kg max 0.3mg per dose IM lateral thigh every 5-15 mins
If child weighs over 25kg, give adult dose
Lay pt supine unless resp compromised, elevate legs - stay supine due to risk of empty ventricle syndrome which can cause large BP drop
Place pregnant pt on left side
Give high flow o2 if needed
Get IV access + aggressive fluids replacement if needed
Check BP, cardiac monitoring, RR, sats, ECG
Give glucagon to pts using BB
Give B2 agonists (Salbutamol) for pts experiencing bronchospasm
Give H1 + H2 blockers (Benadryl and ranitidine) for cutaneous sx
If epi + fluids don’t resolve hypotension, give pressors
If refractory, give IV epi infusion (cardiac epi (1mg) in 1L NS)
Give steroids IV methylprednisone 125mg to prevent recurrence of sx
20% risk of biphasic reaction in anaphylaxis (can have recurrence within 72 hrs)
Anaphylaxis - if epi rec’d, observe. If sx free after 4 hrs can be D/C. If past hx of severe reactions, on BB, significant comorbidity, lives alone or far away - observe for longer
If unclear etiology, refer to allergist + provide epi-pen

Question 14

SJS/ TEN sx

Answer 14

fever, painful diffuse erythema, bullae, oral/mucosal erosions, necrosis and skin sloughing/epidermal detachment

Question 15

Causes of SJS

Answer 15

allopurinol, lamotrigine, anticonvulsants, sulfonamides, COX2i NSAIDs, mycoplasma pneumoniae

Question 16

DRESS - what does it stand for + Sx

Answer 16

Drug Reaction w/ Eosinophilia + Systemic Sx
fever, skin eruption, eosphinophilia (or atypical lymphocytosis), lymphadenopathy, organ involvement

Question 17

DRESS causes

Answer 17

anticonvulsants, sulfonamides

Question 18

RF for peanut allergy

Answer 18

severe eczema, egg allergy

Question 19

Routes for allergy desensitisation

Answer 19

SL, SC

Question 20

What is the PEN-FAST rule?

Answer 20

R/O penicillin allergy if none of the following: <5 yrs since reaction, anaphylaxis, severe cutaneous reaction, treatment required