paediatric allergy Flashcards
What does histamine cause
- bronchial smooth muscle contraction
- Vasodilation
- Seperation of endothelial cells which causes hives
- pain
- itching
What is the presentation of allergy
- Rapid onset
- histamine mediated (hives, swelling and itching with bronchial contraction)
- Urticaria, erythema, angioedema, pallor and wheeze
- Improvement with antihistamines
- Fast improvement of symptoms
What describes a mild/moderate allergic reaction
- Angioedema not involving the airway
- Uritcaria and rash
What describes a severe allergic reaction
- Angioedema of the airway (stridor)
- Bronchospasm
- Hypotension
What investigations are done for allergy
- Skin prick testing
- Specific IgE (RAST)
- Oral food challenge - Gold standard
What should be done before doing skin prick test
- Stop antihistamines for 48 hours before
What is the gold standard investigation for allergy
Oral food challenge - shows what actually happens upon contact or ingestion of the allergen
What is the treatment of angioedema of urticaria
- Avoid triggers
- H1 - antihistamine
- Leukotrine antagonist
- tranexamic acid
- Anti-IgE monoclonal antibody (omalizumab) in children >7 years
What is the presentation of anaphylaxis
- Laryngeal oedema
- Hypotension or collapse
- Bronchospasm
- Feeling of impending doom
- Onset in minutes
What are the dosages in the adrenaline pen for adult and juniors
For anaphylaxis - intramuscular adrenaline (1:1000):
Child >12 - 500Micrograms
Child 6-12 - 300 micrograms
Child 6 months to 6 years - 150 micrograms
Child <6 months - 100-150 micrograms
What is the first line treatment of anaphylaxis
Adrenaline pen
What does adrenaline do
- Reverses effects of histamine
- Bronchodilation
- Decreases angioedema
- Peripheral vasoconstriction
- Improves blood pressure
What is the management of cows milk allergy
- Maternal avoidance of cows milk
- Extensive hydrolysed formula
- Amino acid formula if not tolerated
