Allergy

Question 1

What are the types of food allergies?

Answer 1

• Primary = most common → child has failed to develop immune tolerance
  
  • Infants → cow’s milk, egg, peanut
  • Older children → peanut, fish, shellfish
• Secondary → initially tolerate but become allergic
  
  • Cross-reactivity between proteins in fruit/nuts and pollen → “oral allergy syndrome”

Question 2

What are the signs and symptoms of food allergy?

Answer 2

• IgE mediated allergy
  
  • Urticaria / Rash
  • Facial swelling (angioedema)
  • Erythema
  • Nausea / D&V
  • Colicky abdominal pain
  • Nasal itching / Sneezing / Rhinorrhoea / Congestion
  • Cough / Chest tightness/ Wheeze
  • ANAPHYLAXIS in 10-15 mins
• Non-IgE mediated
  
  • Erythema / Atopic eczema
  • GORD
  • Change in frequency of stools / Constipation / Blood/mucus in stools
  • Abdomen pain / FTT Infantile colic
  • Food aversion
  • Pallor

Question 3

What are the appropriate investigations for a suspected food allergy?

Answer 3

• Allergy-focussed clinical history
• Test 1 = Skin prick allergy testing
  
  • Supports an allergy-focussed history → can confirm diagnosis
• Test 2 = Measurement of specific IgE antibodies (RAST)

Question 4

What questions should be asked in allergy-focussed history?

Answer 4

• Classify the reaction – speed of onset, age of onset, severity, location, reproducibility, history
• Atopic history - personal or FHx
• Food diary
• Details of food avoidance and why
• Details of any feeding history - age of weaning, breast/formula
• Cultural/religious factors surrounding food
• Any previous trial elimination of suspected allergen for 2-6 weeks then reintroduction

Question 5

What are the reasons for referring a child to a food allergy specialist?

Answer 5

• Faltering growth with ≥1 GI symptoms of allergy
• ≥1 acute systemic or severe delayed reactions
• Severe atopic eczema
• Persisting suspicion
• Multiple allergies

Question 6

What is the management of food allergy?

Answer 6

• Avoid relevant foods
• MDT – advice from paediatric dietician to avoid nutritional deficiencies
• Teach family and child how to manage an allergic attack - Allergy Action Plan
  
  • Written information/leaflet + adequate training
    
    • Explain what an allergy is
    • Explain some children grow out of allergies
    • Mild attacks = antihistamines (i.e. loratadine)
    • Severe attacks = EpiPen (IM adrenaline)
• Specialist care if indicated

Question 7

What are the classifications of allergic rhinitis?

Answer 7

• Intermittent vs Persistent
• Mild vs Severe
• Seasonal vs Perennial

Question 8

What are the signs and symptoms of allergic rhinitis?

Answer 8

• Coryza - inflammation / irritation of the mucous membrane of the nose
• Conjunctivitis
• Chronically blocked nose
• Sleep disturbance
• Impaired daytime behaviour / concentration

Question 9

What are the appropriate investigation for suspected allergic rhinitis?

Answer 9

• Exclude other causes
• Identify any co-existent asthma or another atopy
• Examine nose for:
  
  • Nasal polyps
  • Deviated nasal septum
  • Mucosal swelling or depressed or widened nasal bridge

Question 10

What is the management of allergic rhinitis?

Answer 10

• Advise to avoid causative allergen
• Occasional symptomatic relief
  
  • 2-5yo = give oral antihistamine (cetirizine, loratadine) as required
  • Any age = intranasal Azelastine
• Frequent symptomatic relief
  
  • Nasal blockage / Polyps = intranasal corticosteroid (beclomethasone)
  • Sneezing = intranasal corticosteroid or oral antihistamine
• Specific allergen immunotherapy (SCIT = Sub-Cutaneous Immunotherapy)

Question 11

What is Sub-Cutaneous Immunotherapy (SCIT)?

Answer 11

• Solutions of an allergic allergen are injected SC or sublingually on a regular basis for 3-5 years
• Can provide protection for many years but has a risk of inducing anaphylaxis - needs specialist supervision

Question 12

What are the indications for Sub-Cutaneous Immunotherapy (SCIT)?

Answer 12

• Allergic rhinitis
• Conjunctivitis
• Insect stings
• Anaphylaxis
• Asthma

Question 13

What is the management of cow milk protein allergy?

Answer 13

• 1^st = Trial cows’ milk elimination from diet for 2-6 weeks
  
  • Breastfed babies:→ mother to exclude cow’s milk protein from her diet
    
    • Consider prescribing daily supplement of 1g of calcium and 10 mcg of vitamin D
  • Formula-fed babies → replacement of cows’ milk-based formula with hypoallergenic infant formula
  • Weaned infants/older children → exclude cows’ milk protein from their diet
• 2^nd = Regularly monitor growth plus nutritional counselling
• 3^rd = Re-evaluate tolerance to cows’ milk protein (every 6-12 months)
  
  • Re-introduce cows’ milk protein into the diet
    
    • If tolerance is established, greater exposure of less processed milk is advised with ‘Milk Ladder’
• Specialist referral if severe or persistent

Question 14

What counselling should be given to parents with a child with cow milk protein allergy?

Answer 14

• Explain the diagnosis - allergic reaction to one of the 5 proteins in the cow’s milk
• Explain that it is common - 3-6% of infants
• Treatment is simple = avoid cows’ milk in maternal diet or switch to hypoallergenic formula
• Many children grow out of it - review in 6-12m and consider re-introducing cows’ milk protein with milk ladder
• Advise regularly monitoring growth
• Support groups → British Dietetic Association (BDA)