Pediatric Allergy Flashcards
What does mast cell de-granulation cause?
Rapid release of Histamine, Tryptase and Hydrolase and onset of symptoms.
Later release with subsequent effects - secreted inflammatory mediators such as Prostaglandins, Leukotrienes and Cytokines.
What does Histamine do ?
Bronchial and smooth muscle contraction.
Vasodilation.
Separation of endothelial cells (responsible for hives)
Pain and itching
How do you know if what is happening is an allergic reaction ?
Rapid onset. Histamine mediated reactions. Urticaria, itching, angioedema, pallor, sweating and wheeze. Improves with antihistamines. Relatively quick resumption of symptoms.
What are some common food allergies ?
Milk eggs Peanuts Tree nuts Soya Wheat Fish Sesame
What are the common signs and symptoms in a mild/moderate allergic reaction ?
Angioedema (not involving airway)
Urticaria and rash
What are the common signs and symptoms in a severe allergic reaction ?
Angioedema involving airway - Stridor.
Bronchospasm
Hypotension
What are some of the investigations used to test for allergies ?
Skin prick testing.
Specific IgE.
Oral food challenge.
A negative skin prick test is an excellent predictor for what ?
A negative IgE mediated food reaction in patients with anaphylaxis
What do you need to stop before attempting a SPT ?
Antihistamines
What are the benefits of the specific IgE test ?
No need to stop antihistamines prior.
No risk of reactions.
What are the cons of specific IgE ?
Expensive.
Delay in obtaining results.
Less sensitive and specific than SPT.
Highly unreliable results in eczema.
What is the gold standard for allergy testing ?
Oral food challenge
What are the sins and symptoms of anaphylaxis ?
Laryngeal edema Hypotension Bronchospasm Feeling of impending doom Onset usually in minutes
Name some risk factors in anaphylaxis ?
Poorly controlled asthma. Stress. Exercise. Viral infection. Alcohol.
How does adrenaline act to counteract an allergic reaction ?
Reverses peripheral vasodilation
Increases peripheral vascular resistance
Improves BP and coronary perfusion.
Decreases angioedema.
Causes bronchiodilation.
Decreases the release of inflammatory mediators.
What is the management for an allergic reaction ?
Allergen avoidance. Anti-histamine. Adrenaline injectors (Asthma/Anaphylaxis). Dietary advice. Optimise Asthma control.
What kinds of foods cause oral allergy syndrome ?
Celery, fennel and carrots.
Melon, tomato and orange.
What is the symptoms of oral allergy syndrome ?
Itching
Mouth swelling and tongue discomfort
What is the treatment for oral allergy syndrome ?
Antihistamine and avoidance
What is the management of an egg allergy ?
Avoidance
Re-introduction
Egg ladder
What are the symptoms of IgE mediated cow’s milk allergy ?
Rapid onset
Histmine based reaction.
Vomiting and occasionally diarrhea.
How do you identify IgE mediated cow’s milk allergy ?
SPT or specific IgE
How do you identify a non-IgE mediated cow’s milk allergy ?
Not histamine based.
Varying in presentation (bloating, Bleeding PR and irritability)
What is the diagnostic test and management of non IgE mediated cow’s milk allergy ?
No diagnostic test other than dietary management - improves with withdrawal of milk protein
How does a lactose intolerance present ?
Similar to a non-IgE mediated response.
How do you diagnose and manage a lactose intolerance ?
Skin prick test.
Specific IgE
Therapeutic trial of exclusion under dietetic review.
What is the management for IgE - cows milk allergy and non-IgE ?
Maternal avoidance of cows milk - need to supplement Calcium and Vit. D.
EHF Formula.
AA formula if not tolerated.
soya milk >1 years of age or not tolerated the above
What would you include in an allergy focused history and diagnosis ?
Timing of events.
When did it begin, what caused it and how long did the symptoms last ?
What made it better ?
Any atopy in the family ?
What signs would you consider to be indicative of IgE mediated reaction ?
Acute Pruritis. Urticaria. Angioedema. Acute flaring of eczema. Wheeze. Pallor and Sweating.
Which symptoms would you consider to be severe in an allergic reaction ?
Blood/mucous in stool.
Failure to thrive.
Wheeze.
Pallor and sweating.
