What proportion of 10‑year‑old children have celiac disease and what is the recommended diagnostic work‑up?

Prevalence of Celiac Disease in 10-Year-Olds

Approximately 1% of 10-year-old children have celiac disease, though only about one-quarter are actually diagnosed. 1, 2, 3

Epidemiology at Age 10

• The general pediatric population prevalence is approximately 0.7–1%, which applies to 10-year-olds in the general population 1, 4, 2
• However, only 24% of children with celiac disease are ultimately diagnosed, creating a large "celiac iceberg" of undetected cases 1
• The prevalence increases dramatically to 5–10% in high-risk groups such as children with type 1 diabetes, first-degree relatives of celiac patients, or those with autoimmune thyroid disease 5
• First-degree relatives of someone with celiac disease have a 7.5–10% risk 5, 6

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Diagnostic Testing for Celiac Disease

Initial Serologic Testing

Begin with IgA tissue transglutaminase antibodies (TG2-IgA) plus total serum IgA level measured simultaneously. 5, 4, 3

Why This Combination?

• TG2-IgA is the preferred first-line test with the highest accuracy for celiac disease screening 5, 4, 3
• Total serum IgA must be checked concurrently because 1–3% of celiac patients have selective IgA deficiency, which causes falsely negative TG2-IgA results 5, 4
• If IgA deficiency is present, switch to IgG-based tests (IgG tissue transglutaminase or IgG deamidated gliadin peptide antibodies) 5

Interpretation Algorithm

For Children with Very High Antibody Levels:

• If TG2-IgA is ≥10 times the upper limit of normal AND IgA endomysial antibodies (EMA) are positive on a separate blood sample, celiac disease can be diagnosed without duodenal biopsy in children 5, 2, 3
• This biopsy-avoidance pathway is endorsed by European guidelines and increasingly accepted for symptomatic children 5
• HLA-DQ2/DQ8 typing should be checked in patients diagnosed without biopsy to confirm genetic susceptibility 5

For All Other Positive Results:

• Low to moderately elevated TG2-IgA levels require small-bowel biopsy for confirmation 5
• Refer to gastroenterology for upper endoscopy with at least 4 biopsies from the distal duodenum and at least 1 from the bulb 5, 2
• Biopsy is especially important in asymptomatic children before imposing lifelong dietary restrictions 5

Common Pitfall:

• Never start a gluten-free diet before obtaining antibody testing and biopsy, as this will cause antibody levels to normalize and villous architecture to improve, making diagnosis impossible 5

When to Test

Symptomatic Children:

Test immediately if the child presents with: 5, 1, 4

• Chronic diarrhea, steatorrhea (fatty stools), or abdominal pain
• Poor growth, failure to thrive, or unexplained weight loss
• Iron-deficiency anemia refractory to supplementation
• Unexplained fatigue, irritability, or difficulty concentrating
• Dermatitis herpetiformis (intensely itchy vesicles on extensor surfaces)

High-Risk Asymptomatic Children:

Screen at age 10 if the child has: 5, 1

• Type 1 diabetes (screen at diagnosis, then at 2 and 5 years, or if symptoms develop)
• First-degree relative with celiac disease
• Autoimmune thyroid disease
• Down syndrome or Turner syndrome
• Autoimmune liver disease
• Unexplained elevated transaminases

Confirmatory Testing

• EMA (IgA endomysial antibodies) serves as a highly specific second-line confirmatory test when TG2-IgA is positive 5
• EMA is more labor-intensive but has higher specificity than TG2-IgA 5
• Deamidated gliadin peptide (DGP) antibodies have lower accuracy than TG2-IgA and are not recommended for initial screening 5

Genetic Testing

• HLA-DQ2 and HLA-DQ8 testing has a high negative predictive value and can exclude celiac disease if both are absent 5
• However, genetic testing adds no diagnostic value when antibodies are positive and biopsy is planned 5
• Reserve HLA typing for cases where the diagnosis is uncertain or when biopsy-avoidance pathways are used 5

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Key Clinical Context

• Malabsorption symptoms (failure to thrive, chronic diarrhea) increase the accuracy of antibody testing to 98–100% 5
• The pretest probability rises from 1% in the general population to 5–10% in symptomatic children, making serologic testing highly reliable 5, 4
• Children with celiac disease may present with subtle or atypical symptoms, and many are completely asymptomatic, which is why targeted screening of high-risk groups is essential 1, 7