ID: Shirley Williams, 28-year-old mother of two and housewife Isobella Williams, 5-year-old daughter
Live at home with husband and younger child, Harry (2)
PC: Called the ambulance after Shirley noticed her daughter was developing a
widespread rash and was finding it difficult to breathe and swallow
HPC:
- Occurred about 1.5 hours ago whilst Isobella was eating her lunch Isobella likes Asian food and was given Pad Thai bought from a shop Thinks it may have had peanuts sprinkled over it, but not sure
Has avoided giving nuts to children as she heard lots of kids are allergic
- Left room, and when she returned noticed Isobella had developed a rash on her chest and arms
Red, bumpy, ‘looked like hives’ Worsened over 2-3 minutes
- After 5 minutes, noticed Isobella was finding it increasingly difficult to talk and breathe
Tongue and face looked swollen
Making high-pitched noise when she was breathing in Gradually got worse until Isobella was clearly distressed Coughing
- SAAS subsequently called
- Remained conscious throughout - Has never had a previous episode
PMH:
- Previously generally well
- No known allergies to any drugs, foods or insects
- Some reflux as an infant, some mild ‘asthma’ symptoms – very infrequent - Normal vaginal delivery, at term
- Vaccinations given as per schedule - Meeting all milestones, normal growth
FAM:
- Family members all well - Shirley had asthma as a child
DIAGNOSIS:
- Anaphylactic reaction – most likely due to allergy to (pea)nuts - Explanation;
Isobella has had a severe, acute allergic reaction, most likely to peanuts that were in the Pad Thai she was eating
Affects multiple body systems, that is why she had the skin rash and respiratory problems
This is obviously a severe condition, and the risk is that this can happen again if Isobella is exposed to peanuts again
Thus management plan needs to be formulated!
- “But Isobella has never eaten peanuts before. How can she be allergic to
something she has never been exposed to?
So you are correct that allergies occur in people only after they have had an initial exposure to the allergen (a process called sensitization), but in the case of childhood food allergies, it is assumed that sensitization occurs during early exposure to food proteins in breast milk or by allergen skin contact
MANAGEMENT:
- Emergency/Acute mgmt. – already performed by SAAS, patient now stable 1. Remove trigger
2. Administer adrenaline via deep IM injection
o 0.01 ml/kg of 1:1000 adrenaline (max dose 0.5 ml)
3. Establish airway if required and administer high flow oxygen (100%)
o Mechanical ventilation may be required in case of airway obstruction 4. Assess circulation – if hypotensive, administer;
o IV adrenaline dose 0.1 ml/kg of 1:10000 (max dose 3ml) o IV fluids – normal saline 10-20ml/kg as bolus
5. Repeat doses of adrenaline can be administered every 5 minutes until clinical improvement occurs
- Other therapies to consider;
Nebulized salbutamol – recommended if patient is in respiratory distress or is wheezing
Antihistamines – for symptomatic relief of pruritis, second generation preferred Corticosteroids – used mainly for bronchospasm, not commonly used
- The child should be observed for at least 4 hours, and should be admitted under the following circumstances;
Greater than one dose of adrenaline required A fluid bolus is required
Inadequate response to treatment
The child lives a long distance from medical services
- Anaphylaxis action plan; AVOID ALLERGEN
Outlines steps that should be taken if Isobella has a similar episode in the future Will likely require an adrenaline auto-injector (AAI) e.g. Epipen, Anapen, as
Isobella is at ongoing risk if re-exposed to peanuts
http://www.allergy.org.au/health-professionals/anaphylaxis-resources/ascia- action-plan-for-anaphylaxis
Prescription of AAI is via PBS but requires an authority prescription Dosage of AAI;
o Weight <10kg – not recommended for children <10kg o Weight 10-20kg – AAI 150mcg dose
o Weight >20kg – AAI 300mcg dose
- Food allergy testing;
Longer term mgmt., used to confirm food allergy Methods;
o Serology for allergen specific IgE (ASE) o Skin prick testing
Anaphylaxis
- An acute, severe, life-threatening allergic reaction in pre-sensitised individuals, leading to a systemic response caused by the release of immune and
inflammatory mediators from basophils and mast cells - Must involve at least 2 organ systems and must have; At least one respiratory or cardiovascular feature and At least one GI or skin feature
- Most frequently due to allergies to medicines, food, immunotherapy or insect stings
- Exact epidemiology not known
Aetiology & Pathophysiology:
- Common causes of anaphylaxis in children inc;
Foods (most common cause) – nuts, cow milk, eggs, soy, shell-fish, fish, wheat Bites/stings – bee, wasp, ants
Medications – beta-lactams, monoclonal antibodies, anaesthetics
Others – exercise induced, idiopathic, latex, hydatid cyst rupture, biological fluid transfusion (blood, antivenom), food additives
- High-risk groups for anaphylaxis; History of anaphylaxis
Multiple allergy to food and drugs Poorly controlled asthma
Pre-existing lung disease
- Most reactions occur within 30 minutes of exposure to a trigger
- The clinical symptoms are derived from pro-inflammatory and vasoactive mediators and cytokines released by massive degranulation of basophils and mast cells
Classically this cascade is initiated by an IgE-mediated hypersensitivity reaction
Clinical features:
- Respiratory (most common in children); Tongue swelling
Stridor, dysphasia
Hoarse voice, change in character of cry Persistent cough
Wheeze
Feeling of swelling/tightness in throat - Cardiovascular;
Pale, floppy – infants Palpitations
Tachycardia/bradycardia Hypotension
Cardiac arrest - GI;
Nausea and vomiting Diarrhea
Abdominal/pelvic pain - Mucocutaneous; Generalized pruritis
Urticarial/intense erythema
Conjunctival erythema and tearing Flushing
Angio-oedema - Neurological;
Headache (usually throbbing) Dizziness
Confusion, altered consciousness Collapse with or without LOC
Investigations: Clinical diagnosis!