What Labcorp serum labs should I order to rule out dairy and wheat allergies in a 1-year-old patient?

Serum IgE Testing for Dairy and Wheat Allergy in a 1-Year-Old

Order specific IgE testing for cow's milk (dairy) and wheat only if the child has already experienced symptoms within minutes to hours after ingesting these foods, or has moderate-to-severe atopic dermatitis that persists despite optimal topical treatment. 1, 2

When Testing is Appropriate

Testing should be ordered in these specific scenarios:

• History of immediate reaction: The child developed symptoms (hives, vomiting, respiratory symptoms, facial swelling) within minutes to 2-3 hours after consuming dairy or wheat 1
• Moderate-to-severe atopic dermatitis: The child under 5 years has persistent eczema despite appropriate-potency topical corticosteroids and adequate emollient use 2, 3
• Reliable temporal relationship: There is a consistent, documented pattern of symptoms occurring reproducibly with exposure to the suspected food 3

Specific Tests to Order at LabCorp

For dairy allergy evaluation:

• Cow's milk-specific IgE (serum test) 1, 4

For wheat allergy evaluation:

• Wheat-specific IgE (serum test) 1, 4

Critical Pitfalls to Avoid

Do not order testing without a clinical history of symptoms. 1, 2 A positive IgE test in the absence of clinical symptoms only indicates sensitization, not true food allergy—the positive predictive value is less than 50%, meaning most positive results are false positives. 1, 2

Avoid ordering broad food allergy panels. 1 Laboratory-offered standard panels of common foods should be discouraged. Only test for foods that reasonably may have provoked a documented reaction. 1

Never diagnose food allergy based on testing alone. 1, 4 Testing without suspicion of a symptom-provoking episode is misleading and often inaccurate because of false-positive results. 1

What Happens After Testing

• Positive test result: This requires correlation with clinical history and referral to a pediatric allergist for supervised oral food challenge to confirm the diagnosis 1, 2
• Negative test result: Has excellent negative predictive value (>95%), making food allergy very unlikely 1
• Any confirmed allergy: Prescribe epinephrine autoinjector and antihistamines, provide training on use, and refer to allergist for longitudinal care 1

When NOT to Test

Do not order testing if the child only has:

• Colic, irritability, or normal infant fussiness 1
• Isolated rash without moderate-to-severe atopic dermatitis 3
• Family history of food allergy but no personal symptoms 1
• Parental concern without documented symptoms 3

In these cases, reassurance and optimization of any underlying issues (like proper eczema treatment) is more appropriate than testing. 1, 3