Allergy Flashcards
Clinical features of IgE food allergy?
Skin - urticarial rash (redness, swelling, itch)
GIT - N+V, diarrhoea
Sensory - perioral numbness/tingling
Resp - hoarseness, nasal congestion, SOB, wheeze, chest tightness
Cardio - tachy/palpitations, dizziness, syncope
Swelling - throat, tongue
Symptoms occur minutes - 2 hours (usually <1hr)
High-risk groups for anaphylaxis?
Hx previous anaphylaxis Multiple food/drug allergies Lung disease, poorly controlled asthma older age Beta-blockers, ACEI
Key history points for child presenting with suspected food allergy?
- What was ingested? i.e. whole food or a derivative
- Amount - large quantity or just touched lips
- How cooked - raw or cooked into meal
- Timing relationship b/w ingestion & symptoms
- Symptoms of allergy and anaphylaxis
- Previous exposures, previous possible reactions
- Other allergies?
- Lung disease? Asthma? medications?
What advice/management would you give to child/parents after an non-anaphylactic allergy in the acute setting?
- Identify trigger and avoid - educate on sources and trace sources
- Develop and explain an management plan for accidental exposures - advise to discuss and distribute to the school etc
- Advice on symptom management - cold compress, oral antihistamines and OBSERVATION - what signs to look for if anaphylaxis and what to so
- Explain Ix that need to be performed and educate on natural history of allergies
- Organise outpatient apt and follow-up
What Ix for allergies?
Skin prick testing - high sensitivity (unless demographism), quick, cheap. Positive if wheal >= 3mm bigger than saline control. The larger the wheal the more likely a true IgE allergy, but can’t tell you about the severity of allergy
Serum IgE - less sensitive and more expensive than SPT. Useful in primary setting for diagnosing single suspected allergy reaction
Food challenge - gold standard for diagnosis, used if other tests unequivacol, needs to be done in specialised setting due to risk of anaphylaxis
What are the most common food allergens of IgE mediated allergy? Which ones typically resolve and which persist into adulthood?
Resolve - wheat, cow’s milk, soy, ?eggs
Persist - fish, shellfish, peanut, treenut
What are examples of mixed IgE/non-IgE food allergic reactions?
Eosinophilic oesophagitis - cows milk, soy, wheat, egg
Atopic dermatitis
What are examples of non-IgE mediated food allergies and allergens typically cause them?
Proctocolitis - Breast milk, cow, soy milk
Enteropathy - cow milk
FPIES - cow, soy milk, rice
What is proctocolitis?
Delayed reaction to ingestion of breast milk, formula or whole cow/soy milk
Typically more mild disease symptoms and child is otherwise well with normal growth
Blood streaked, mucus stools and mild diarrhoea
Typically resolves after 18-24 months
What is enteropathy?
Delayed reaction to formula or whole cow milk
More severe disease than proctocolitis - associated with weight loss and FTT
Bloody stools/rectal bleeding, profuse vomiting, chronic diarrhoea, abdo pain and distention
Typically resolves after 18-24 months
What is FPIES?
Delayed reaction after ingestion of formula or whole cow/soy milk but with acute onset symptoms
Vomiting, bloody diarrhoea and possible hypovolaemic shock - babu acutely unwell
Typically occurs after first ingestion
What is the acute management for anaphylaxis?
IM 0.01 mg/kg adrenalin - repeat every 5 minutes as neccessary
Call for help
ABCD - high flow oxygen and posture (supine, elevated legs), fluid bolus and adrenalin infusion
Adjunctive meds of limited benefit - antihistamines, corticosteroids, salbutamol
What advice would you give in the ED after an anaphylactic reaction?
- Educate on trigger and importance of avoidance
- Develop anaphylaxis management plan and discuss with them, ensure they will distribute to others
- Educate on Epipen, when to use and how to use - demonstrate to them
- ?medialert bracelet
- Discuss Ix and follow-up - will need outpatient review with skin prick test +/- controlled food challenge
- Natural history of allergy
