Cow's Milk Protein Allergy

Question 1

What is Cow’s Milk Protein Allergy?

Answer 1

• immune mediated allergic response to milk proteins casein and whey

Question 2

What is the difference between IgE mediated and Non-IgE mediated?

Answer 2

• IgE mediated: A type 1 hypersensitivity reaction. CD4+ TH2 cells stimulate B cells to produce IgE antibodies which trigger the release of histamine and cytokines
• Non - IgE mediated: involves T cell activation against cow’s milk protein

Question 3

What are the Risk Factors for Cow’s Milk Protein Allergy?

Answer 3

• History of Atopy (asthma, eczema, allergic rhinitis)
• Family History of Atopy

Question 4

What is a Protective Factor for Cow’s Milk Protein Allergy?

Answer 4

• Breastfeeding

Question 5

What are the clinical features of IgE-mediated Cow’s Milk Protein Allergy?

Answer 5

• Speed: Acute and rapid onset (2 hours)
• Skin Reactions: Pruritus, Erythema, Urticaria, Angio-oedema
• GI Symptoms: Angioedema, Nausea, Abdominal Pain, Vomiting, Diarrhoea
• Respiratory Symptoms: Lower Respiratory Tract Symptoms, Upper Respiratory Tract Symptoms

Question 6

What are the clinical features of non-IgE mediated Cow’s Milk Protein Allergy?

Answer 6

• Speed: Non-acute and delayed (48hours)
• Skin Reactions: Pruritus, Erythema, Atopic Eczema
• GI symptoms: Loose/ frequent stools, blood/ mucus in stools, abdo pain, constipation, food refusal, Pallor and tiredness
• Respiratory Symptoms: Lower Respiratory Tract Symptoms

Question 7

When should you consider CMPA?

Answer 7

• Atopic Eczema
• GORD
• Chronic Gastrointestinal Symptoms

Question 8

What would you see on Examination for CMPA?

Answer 8

• Gastrointestinal Examination - showing malnutrition
• Review Growth Charts
• Signs of Atopic Co-morbidities (Eczema, asthma and allergic rhinitis)

Question 9

What are the differential Diagnosis?

Answer 9

• Food intolerance
  -Meckel’s Diverticulum
• Chronic Gastrointestinal Disease (coeliac, GORD, IBD, constipation)
• Pancreatic Insufficiency - Cystic Fibrosis
• UTI

Question 10

What Investigations would you do for CMPA?

Answer 10

• ## Blood Test looking for specific IgE antibodies (RAST test)

Question 11

When would you refer for a RAST test?

Answer 11

• Faltering growth
• Acute systemic/ delayed reactions
• Confirmed IgE-mediated food allergy with asthma
• Persistent parental suspicion of food allergies

Question 12

What is the Managment of Cow’s Milk Protein Allergy?

Answer 12

• Managed by avoidance of cow’s milk in all forms - including mother’s diet if breast feeding
• This elimination diet is required for at least 6 months or until the infant is 9-12 months with re-evaluation every 6/12 months to check tolerance
• Nutritional counselling and regular monitoring of growth
• Infants who are formula fed are given- hypoallergenic formula:
  1. Extensively Hydrolysed formula: cheaper, first-line formula made from cow’s milk and the casein and whey are broken down into smaller peptides which are less immunogenic
  2. Amino Acid Formula: more expensive, second line formula for the children who continue to have symptoms despite using the hydrolysed formula
• Soya based formulas not recommended in infants < 6months

Question 13

What are the complications of CMPA?

Answer 13

• Malabsorption and faltering growth