Immediately stop the full-cream cow's milk and return to exclusive soy milk
The excessive nighttime crying that began after introducing full-cream cow's milk strongly suggests cow's milk protein allergy, and you should eliminate all cow's milk from the child's diet immediately. 1
Why This Matters
Cow's milk protein allergy can present as excessive crying, particularly at night, in infants and young children. The temporal relationship—crying started after introducing cow's milk—is the key diagnostic clue here. Research has documented that infants with cow's milk allergy experience disrupted sleep patterns, waking frequently and crying excessively, with symptoms resolving within 1-2 weeks of eliminating cow's milk 2.
Immediate Management Steps
Step 1: Complete elimination
- Remove all full-cream cow's milk immediately
- Return to exclusive soy milk feeding
- Continue soy milk for at least 2-4 weeks to assess symptom resolution
Step 2: Monitor for improvement
- Expect crying to decrease within 1-2 weeks if this is cow's milk allergy 2
- Track nighttime awakenings and crying episodes
- Document any other symptoms (rash, vomiting, diarrhea, poor weight gain)
Step 3: Consider alternative formulas if soy is inadequate If the child is under 6 months or if you need to transition away from soy eventually, extensively hydrolyzed formulas are the gold standard for confirmed cow's milk protein allergy 1. However, be aware that there is potential cross-reactivity between cow's milk and soy proteins in some children with FPIES (Food Protein-Induced Enterocolitis Syndrome), so cautious introduction of soy is warranted, especially in infants under 6 months 1.
Important Caveats
Do not attempt a milk challenge at home. If you want to confirm the diagnosis after symptoms resolve, this should be done under medical supervision, as reintroduction can cause severe recurrence of symptoms within days 2.
Monitor growth parameters (weight, length, head circumference) regularly, as children with food protein allergies can experience poor weight gain if the offending protein continues in the diet 1.
Avoid the common pitfall of continuing both milks together or doing a gradual transition—this will perpetuate symptoms. The elimination must be complete and immediate.
When to Seek Further Evaluation
Consider formal allergy evaluation if:
- Symptoms don't improve within 2 weeks of complete cow's milk elimination
- The child has other signs of atopy (eczema, wheezing, family history of allergies) 3
- There are concerns about multiple food intolerances
- Growth parameters are affected
The evidence strongly supports that most children with cow's milk-induced reactions develop tolerance by 1-3 years of age, with 60% tolerating by age 1 year and 85% by age 3 years 1. However, this child needs immediate symptom relief now through complete elimination.