What are the assessment, diagnosis, and initial management strategies for Cow's Milk Protein Allergy (CMPA) in London, UK?

Assessment, Diagnosis, and Initial Management of Cow's Milk Protein Allergy (CMPA) in London, UK

Cow's milk protein allergy (CMPA) should be diagnosed through a structured approach using elimination diet followed by challenge testing, with management based on the severity and type of reaction (IgE vs non-IgE mediated). 1

Clinical Assessment

Key Symptoms to Identify

IgE-Mediated CMPA (Immediate Reactions):

• Skin: Urticaria (hives), angioedema, erythema
• Gastrointestinal: Vomiting, diarrhea, abdominal pain
• Respiratory: Wheezing, rhinitis, coughing
• Cardiovascular: Hypotension (in severe cases)
• Timing: Symptoms typically appear within minutes to 2 hours after ingestion

Non-IgE-Mediated CMPA (Delayed Reactions):

• Gastrointestinal: Persistent diarrhea, vomiting, blood in stool, failure to thrive
• Skin: Atopic dermatitis, eczema
• Timing: Symptoms typically appear 2-72 hours after ingestion
• Other: Irritability, feeding difficulties, sleep disturbance

Risk Factors to Consider

• Family history of atopy
• Presence of other allergic conditions (eczema, asthma)
• Early introduction of cow's milk formula

Diagnostic Approach

Step 1: Initial Clinical Evaluation

• Detailed history of symptoms and their relationship to milk consumption
• Physical examination focusing on growth parameters, skin, respiratory and GI systems
• Document timing, consistency and severity of symptoms

Step 2: Testing Options

1. For suspected IgE-mediated CMPA:

   • Skin prick test (SPT)
   • Serum-specific IgE testing
   • Note: Positive tests indicate sensitization but not necessarily allergy 1

2. For suspected non-IgE-mediated CMPA:

   • Elimination diet is the primary diagnostic tool
   • Atopy patch testing may be considered but is not routinely recommended 1

Step 3: Elimination Diet (Gold Standard)

• Complete elimination of cow's milk protein for:
  • 2-4 weeks in IgE-mediated cases
  • 2-6 weeks in non-IgE-mediated cases 1

Step 4: Confirmation by Challenge

• Oral food challenge (OFC) is the definitive diagnostic test
• In the UK, this should be performed under medical supervision
• Double-blind placebo-controlled food challenge (DBPCFC) is the gold standard but often impractical in routine clinical settings 1

Initial Management

For Breastfed Infants

• Continue breastfeeding as the preferred option
• Maternal elimination diet (remove all dairy products)
• Consider calcium and vitamin D supplements for the mother
• Monitor infant's growth and symptoms 1

For Formula-Fed Infants

1. First-line: Extensively hydrolyzed formula (eHF)
2. If symptoms persist or in severe cases: Amino acid formula (AAF)
3. Not recommended: Soy formula in infants under 6 months, partially hydrolyzed formula, other mammalian milks (goat, sheep) 1

Nutritional Considerations

• Ensure adequate calcium intake
• Monitor growth and development
• Consider referral to a pediatric dietitian for nutritional guidance

Medication Management

• For mild-moderate reactions: Antihistamines may be prescribed
• For severe reactions: Epinephrine auto-injector should be prescribed with training on its use 1

Referral Criteria for Specialist Care in London

Immediate Referral (Emergency)

• Anaphylaxis or severe immediate reactions
• Failure to thrive with significant weight loss

Urgent Referral

• Multiple food allergies
• Significant feeding difficulties
• Persistent symptoms despite appropriate elimination diet

Routine Referral

• Diagnostic uncertainty
• Need for supervised food challenge
• Parental anxiety requiring specialist support

Follow-up and Monitoring

• Review within 2-4 weeks after starting elimination diet
• Regular monitoring of growth parameters
• Reassessment for tolerance development:
  • Every 6-12 months for children under 2 years
  • Every 12-18 months for older children 1

Common Pitfalls to Avoid

1. Overdiagnosis: Not all adverse reactions to cow's milk are allergic; distinguish from lactose intolerance and other gastrointestinal disorders 1

2. Unnecessary dietary restrictions: Prolonged elimination diets without confirmed diagnosis can lead to nutritional deficiencies 1

3. Delayed diagnosis: Non-IgE-mediated CMPA is often missed or diagnosed late due to non-specific symptoms 2

4. Inappropriate formula choice: Using partially hydrolyzed formulas instead of extensively hydrolyzed or amino acid formulas for treatment 1

5. Inadequate parent education: Parents need clear guidance on reading food labels and avoiding hidden milk proteins 2

By following this structured approach to assessment, diagnosis, and management, healthcare providers in London can effectively address CMPA in infants and children while minimizing unnecessary dietary restrictions and ensuring optimal nutrition and growth.