Allergy Flashcards
What is an allergy?
Geneti susceptibility resulting in an abnoral reaction to an environmental allergen
What is the commonest chronic disease in children?
Allergy
What percentage of children in the UK suffer fro allergy?
40%
What is specific allergen immunotherapy?
Solutions of allergen are injected SC or sublingually on reg basis for 3-5 years with the aim of developing immune tolerance
Are most allergies in children primary or secondary?
Primary - failed to ever build tolerance
Hypersensitivity
Reproducible signs/symptoms following exposure to a defined stimulus at a dose tolerated by normal people
Allergy
Hypersensitivity reaction IgE or non-IgE
Given an example of a non-IgE mediated allergy
Coeliac
Atopy
Personal/familial tendency to produce IgE antibodies to normal stimuli
Categories of allergic rhinitis
Atopic vs Non-atopic
Intermitten vs persistent
Mild vs severe
Seasonal vs perennial
What percentage of children suffer from allergic rhinitis?
20%
Signs/symptoms allergic rhinitis
Conjunctivitis
Coryza
Coughing (+/- post nasal drip)
Mouth breathing, halitosis (chronic nasal congestion)
Sleep disturbance
Impaired behaviour
Reduced concentration
–> Affecting school performance
Sepcifics to look out for allergic rhinitis
Monitor closely for asthma/other atopy
Check for nasal polyps/narrowing/deviated nasal septum
Identify most likely causative agent(s)
Mouth breathing
Dry mouth
Halitosis
Allergic rhinitis management (intermittent mild)
Allergen avoidance
Oral/intranasal antihistamine
LTRA
Allergic rhinitis management (persistent mild)
Allergen avoidance
Oral/intranasal antihistamine
Intranasal corticosteroids
SL/SC immunotherapy
+Intranasal decongestant
+Nasal saline irrigation
Allergic rhinitis management (persistent moderate to severe)
Allergen avoidance
Intranasal corticosteroids
Intranasal antihistamine
+Intranasal decongestant
+Nasal saline irrigation
+ INTRANASAL IPRATROPRIUM
What percentage of infants may have cow’s milk protein allergy?
15%
Signs/symptoms cow’s milk protein allergy
Resp - wheeze, coryza, cough, dribble
Gastro - vom, diarrhoea, constipation, wind
Skin - eczema, hives, angiodema, dermatitis
(Starting when using starting formula with cow’s milk protein, or in infants exclusively breastfed by mothers drinking cow’s milk)
Management for CMPA in breastfed infants
Mother should avoid drinking cow’s milk
(Consider calcium and vitD)
Paediatric dietician
Monitor for growth
Regular ax for allergy (many children grow out)
MILK LADDER beginning at 1 year
Management for CMPA in formula fed infants
Change formula to hypoallergenic:
- Hydrolysed - Aptamil pepti 1
- Amino acid if severe
Paediatric dietician
Monitor for growth
Regular ax for allergy (many children grow out)
MILK LADDER beginning at 1 year
Management of CMPA in children
Remove cow’s milk from diet
Dietician input for nutritional counselling
Paediatric dietician
Monitor for growth
Regular ax for allergy (many children grow out)
MILK LADDER beginning at 1 year
What is a milk ladder?
If tolerance to CMP is established, gradual exposure of less processed milk
What is the most common pathophysiology of food allergy?
(Usually) IgE mediated reaction to environmental allergen. Most are primary, meaning the individual failed to ever develop tolerance to allergen
Wht is food intolerance?
Non-immunological hypersensitivity to allergen
Commonest food allergens in infants?
CMP, egg, peanut
Commonest food allergens in children?
Peanut, tree nut, (Shell)fish
Symptoms of IgE mediated food allergy
Acute onset (10-15 mins)
- Resp symptoms: wheeze, stridor
Angiodema
Urticaria
–> SHOCK
Symptoms of non-IgE mediated food allergy
Insidous onset (over hours) - GI symptoms: abdo pain, DNV, FTT
Which food allergies have a positive skin prick test? Which have negative?
+ve: IgE
-ve: non-IgE
How are IgE mediated food allergies diagnosed?
Skin prick testing or specific IgE Abs in blood
Food challenge
How ae non-IgE mediated food allergies diagnosed?
Endoscopy and intestinal biopsy (eosinophilic infiltrates)
Food challenge
Management of mild food allergies (no cardioresp symptoms)
Educate child and parents. Allergy action pain
AVOID TRIGGERS Anti histamines (non sedating)
Management of severe food allergies (cardioresp symptoms)
Educate child and parents
Allergy action plan
IM ADRENALINE (epipen) - <30kg = 0.15mg, >30kg = 0.3mg Salbutamol if bronchospasm
Dosages for epipens
<30kg = 0.15mg >30kg = 0.30mg
How is severity of urticaria assessed?
Urticaria activity score
Management for symptomatic urticaria
Non-sedating antihistamine (e.g. cetirizine)
Oral pred
Daily antihistamines if persistent
Refractory: LTRA, or anti-IgE antibody
Name a non-sedating antihistamine
Cetirizine
What is omalizumab?
Anti-IgE antibody
