Celiac Disease in Children: Growth, Testing, and Diet Adherence

Why Growth Delays Might Be a Sign of Celiac Disease

When a child isn’t growing as expected, parents often blame poor appetite, picky eating, or genetics. But sometimes, the real culprit is something hidden in their food-gluten. Celiac disease is an autoimmune condition where the body attacks the small intestine after eating gluten, a protein found in wheat, barley, and rye. In kids, this isn’t just about stomachaches. It’s about stunted growth, delayed puberty, and tired, weak bodies that don’t seem to catch up. The damage happens because the tiny finger-like projections in the gut-called villi-get flattened. Without them, nutrients can’t be absorbed. And without proper nutrition, kids can’t grow.

Studies show that up to 1 in 133 children in the U.S. have celiac disease, and many aren’t diagnosed until they’re already falling behind on growth charts. One study found that 4% of kids seen for short stature had undiagnosed celiac disease. That’s not rare. It’s common enough that every pediatrician should consider it when a child’s height or weight stops climbing. The good news? Once gluten is removed, most kids start growing again. But timing matters. The earlier the diagnosis, the better the outcome.

How Celiac Disease Is Tested in Kids

Testing for celiac disease in children isn’t just one blood test. It’s a step-by-step process designed to avoid false alarms and unnecessary procedures. The first step is always a blood test for tissue transglutaminase antibodies (tTG-IgA). This test is 98% accurate when done right. But there’s a catch: some kids are IgA deficient, which can make the test look negative even if they have celiac. That’s why doctors also check total IgA levels.

If the tTG-IgA is high-specifically 10 times above the normal limit-and the child has symptoms like poor growth, diarrhea, or abdominal pain, a new guideline from ESPGHAN allows doctors to skip the biopsy in about half of cases. That’s a big change from just a few years ago. But only if two other things are true: the child has the HLA-DQ2 or HLA-DQ8 genes (which 95% of celiac patients have), and their symptoms match the disease. If the blood test is only slightly high, or if symptoms are unclear, a biopsy is still needed.

During the biopsy, a tiny sample of the small intestine is taken through an endoscope. In active celiac disease, the villi are flattened-what doctors call Marsh 3 lesions. This is the gold standard for diagnosis. Bone age X-rays are also often done. If a child’s bones are delayed by 1.5 to 2.5 years compared to their actual age, that’s a strong sign celiac is behind their growth delay. And here’s the hopeful part: kids with delayed bone age are more likely to catch up fully after starting a gluten-free diet.

How Growth Recovers After Starting a Gluten-Free Diet

Once gluten is gone, the body starts healing. But healing doesn’t happen all at once. Weight usually improves first-often within six months. Kids gain pounds quickly as their gut absorbs nutrients again. But height? That takes longer. Most children need 18 to 24 months to show real catch-up growth in height.

There are three patterns doctors see. The first is rapid catch-up: kids under age 3 who are diagnosed early often zoom back to their normal growth curve within a year. The second pattern is slower but steady: kids diagnosed later grow a bit faster than their peers, but only because their bones are still developing. Their growth spurt lasts longer, so they end up at a normal adult height. The third pattern is delayed maturation: their growth speed looks normal, but their body is just taking its time. Bone age delays mean they’ll keep growing longer than other kids their age.

One study followed 24 children with delayed diagnosis. At diagnosis, their height was almost two standard deviations below average. After three years on a gluten-free diet, they’d gained nearly 0.8 standard deviations. That’s a huge improvement. And 85% of children reach their expected final height if they stick with the diet. The key? Early diagnosis. Kids diagnosed before age 5 have a 98% chance of reaching their target height. After age 10, that drops to 85%. That’s why waiting is risky.

Why Diet Adherence Is Harder Than It Sounds

Going gluten-free sounds simple: no bread, no pasta, no cereal. But it’s not. Gluten hides in soy sauce, malt flavoring, processed meats, and even some medications. Cross-contamination is a huge problem-using the same toaster for gluten-free and regular bread can trigger symptoms. One study found that 40-50% of households accidentally expose their child to gluten this way.

And it’s expensive. Gluten-free products cost 156% to 242% more than regular ones. For many families, that’s a financial burden. Then there’s social pressure. Teenagers don’t want to be the kid who can’t eat pizza at parties or lunchroom spaghetti. One 14-year-old shared that they’d sneak gluten occasionally because they felt left out-and ended up with stomach pain and fatigue. Adherence drops sharply after age 12. Teens are 25-35% less likely to stick with the diet than younger kids.

But here’s what works: education. Families need at least three to five sessions with a pediatric dietitian to learn how to read labels, avoid hidden gluten, and plan meals. Schools matter too. Over half of children with celiac get exposed at school. A 504 plan-a legal document that ensures accommodations-is essential. It means the school must provide safe food, train staff, and keep shared areas clean.

What to Monitor Beyond Growth

Growth is the most visible sign of celiac disease, but it’s not the only thing that needs checking. Iron deficiency hits 30-50% of kids at diagnosis. Many have anemia-low red blood cells-because their gut can’t absorb iron. Vitamin D is another big one. Up to 60% of newly diagnosed children are deficient. That leads to weak bones, rickets, and long-term risks like osteoporosis. Folate and B12 levels also drop because the gut can’t absorb them properly.

That’s why regular blood tests are part of care. Every three to six months, doctors check ferritin, vitamin D, folate, and B12. Supplements are often needed. Iron supplements might be given for a few months. Vitamin D doses can be high at first-5,000 IU daily-until levels normalize. Bone density scans may be done after 18-24 months on the diet to see if the bones have recovered.

Even if a child looks better, the tTG-IgA blood test should be checked every 6-12 months. If it stays high, something’s wrong. Maybe they’re still eating gluten. Maybe they have another condition. Persistent antibodies mean the gut isn’t healing-and that raises the risk of complications like lymphoma later in life.

When Growth Doesn’t Improve-What Then?

Most kids do well on a gluten-free diet. But 5-10% don’t. Their weight might improve, but their height stays low. Their antibodies stay high. Their energy doesn’t bounce back. When that happens, it’s time to dig deeper. The first question: are they really avoiding gluten? Sometimes, it’s accidental. Other times, it’s intentional. A dietitian might do a food diary review or check for hidden sources like cross-contaminated oats or gluten in cosmetics.

If diet is clean and they still aren’t growing, other causes must be ruled out. Growth hormone deficiency, thyroid problems, or other autoimmune conditions like type 1 diabetes can coexist with celiac. A pediatric endocrinologist may be needed. One expert noted that children with delayed bone age at diagnosis almost always catch up. But those with normal bone age? Only 65% reach their target height. That’s why early diagnosis matters-not just for growth, but for knowing what to expect.

What’s Next for Celiac Disease Treatment?

Right now, the only treatment is a lifelong gluten-free diet. But research is moving fast. Drugs like larazotide acetate are in trials. This drug helps seal the gut lining so gluten doesn’t trigger an immune reaction. Early results show it can cut symptoms by 30% when gluten is accidentally eaten. It’s not a cure, but it could be a safety net for kids who slip up.

Another approach, Nexvax2, was an immunotherapy vaccine meant to desensitize the immune system to gluten. But it failed in Phase 2 trials and was paused. Other ideas-like enzymes that break down gluten in the stomach-are still being tested. None are approved yet. For now, the diet remains the only proven solution.

But here’s the most important takeaway: celiac disease doesn’t have to limit a child’s future. With early testing, strict diet, and good support, kids grow, thrive, and live full lives. The key is not just diagnosis-but consistent, lifelong care.