At what age is celiac disease typically diagnosed?

Age of Celiac Disease Diagnosis

Celiac disease is most commonly diagnosed during early to middle childhood, with a median age of diagnosis around 6-7 years, though it can present at any age from infancy through adulthood.

Typical Age Distribution at Diagnosis

The age at which celiac disease is diagnosed shows distinct patterns across childhood and into adulthood:

• Peak diagnostic age occurs between 3-12 years, with approximately 66% of pediatric cases diagnosed during this window 1, 2
• Median age at diagnosis is approximately 6.8 years in pediatric populations 3
• Early childhood (under 3 years) accounts for 15-18% of pediatric diagnoses 3, 2
• School-age children (6-12 years) represent 34-35% of cases 2
• Adolescents (12-18 years) comprise 16% of pediatric diagnoses 2

Adult vs. Pediatric Diagnosis Patterns

A substantial proportion of celiac disease is diagnosed after childhood:

• Approximately 65% of all celiac disease cases are diagnosed after age 18, with a mean age of 29 years in adult populations 4, 1
• The median duration of symptoms before diagnosis is 3.5 years in children compared to 4.9 years in adolescents and adults, indicating longer diagnostic delays in older patients 1
• Most cases diagnosed in association with type 1 diabetes occur within the first 5 years after diabetes diagnosis, regardless of the patient's age at diabetes onset 5

Age-Related Clinical Presentation Differences

The clinical manifestations vary significantly by age at presentation, which influences when diagnosis occurs:

Younger Children (Under 6 Years)

• Present more frequently with classic malabsorptive symptoms including chronic diarrhea (74% in children vs. 59% in adults), weight loss, abdominal distention, and failure to thrive 4, 1, 2
• Have higher tissue transglutaminase (TTG) antibody levels, often exceeding 10 times the upper limit of normal 2
• Show more severe nutritional deficiencies including hypoalbuminemia and zinc deficiency 2

Older Children and Adolescents

• More likely to present with atypical or subtle manifestations such as isolated short stature, iron deficiency anemia without gastrointestinal symptoms, or elevated liver enzymes 4, 3
• Iron deficiency is present in 61% of children with celiac disease but may be the sole presenting feature in older children 3
• Approximately 44% of patients present to non-gastroenterology specialists with atypical manifestations, contributing to diagnostic delays 4

Important Clinical Considerations

Diagnostic Delays

• The absence of intestinal symptoms does not preclude celiac disease diagnosis; many children, particularly older ones, do not report gastrointestinal complaints 3
• A high index of suspicion is required for diagnosing variant forms, especially in school-age children and adolescents who may present with minimal or atypical symptoms 4

High-Risk Populations Requiring Earlier Screening

• Children with type 1 diabetes should be screened soon after diabetes diagnosis, as most celiac disease cases in this population are identified within the first 5 years 5
• First-degree relatives of celiac disease patients have a 10-15% lifetime risk and should be tested when symptoms develop 6
• Children with Down syndrome or autoimmune thyroid disease warrant screening even in the absence of typical symptoms 6

Gender Differences

• Girls are diagnosed more frequently than boys across all age groups, with a statistically significant female predominance 3

The variability in age at diagnosis reflects both the diverse clinical presentations of celiac disease and the evolution of diagnostic awareness and screening practices over time.