Bellyaches, stomachaches, tummy trouble … You're familiar with all of these terms, but what about allergic GI disease? Could your child be suffering from this and you don't even know it?

Allergic GI disease, with symptoms that range from mild food sensitivities to severe allergies, is a widespread problem, striking as many as 8 percent of babies by the time they reach their first birthday. And research shows that the number of children affected is on the rise, especially among those with more serious cases.

By definition, allergic GI disease is an immune reaction to a certain food or ingredient that causes a range of unpleasant symptoms, including irritability, gastrointestinal discomfort, diarrhea, vomiting, bloody stools, mild eczema, and, in the most severe cases, weight loss and malnutrition. Despite these manifestations, allergic GI disease can be difficult to diagnose. "Infants and very young children can't really communicate about what they're experiencing, and the symptoms of allergic GI disease are often easily written off as a number of other issues," says Owen Koslowe, MD, a pediatric gastroenterologist at Goryeb Children's Center at Overlook Medical Center. "So if parents notice that their child is chronically ill after eating, they should definitely share their concerns with their pediatrician."

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In infancy, the biggest allergy triggers tend to be cow's milk protein and soy. These usually can be easily avoided by switching to a different formula, but as kids grow, allergies
to other foods like eggs, seafood, and nuts also can arise. "This is why pediatricians advise parents to expand their children's diets slowly—one new food at a time—so if problems arise, the culprit is clear," explains Koslowe. In other words, a diet that becomes too varied, too quickly, can make the process of determining exact allergy triggers more difficult and
time-consuming.

On top of being tricky to diagnose, the root cause of allergic GI disease is equally mysterious. "We really don't fully understand what causes food allergies and sensitivities and why cases of allergic GI disease are exploding in developed countries like the United States," says Koslowe. One theory is based on the hygiene hypothesis, which suggests that parents and healthcare professionals in developed nations may be going too far in excluding certain foods during infancy—when the immune system should be learning to tolerate some foreign proteins—thereby causing the immune system to become over-reactive. This theory is supported by research that shows that babies with food allergies are also more likely to develop other autoimmune conditions like asthma and eczema. "It's possible that if we introduce babies to new foods earlier, they may become better desensitized to allergy triggers," says Koslowe, "but more research definitely needs to be done in this area."
When it comes to managing allergic GI disease, Koslowe confirms that avoiding triggers is the best strategy, but it's not always that simple. "Depending on the severity of the symptoms, other treatments may be indicated," he says. Allergy specialists may try to desensitize the child's body to certain triggers in an attempt to mitigate more severe reactions; as the child grows, these same desensitizing techniques can be used to determine whether a child is still allergic to specific triggers. "By the time a patient is nine or ten, many food allergies often are outgrown, depending on the type of trigger and how serious the reaction," Koslowe explains. "But parents should always consult with their pediatrician or allergist before re-introducing trigger foods, rather than testing them on their own."

Over the last ten years, a condition similar to gastroesophageal reflux disease (GERD) also has seen a rapid increase in new cases. Eosinophilic esophagitis (EoE), or allergic esophagitis, is an allergic inflammatory condition of the esophagus. EoE symptoms—vomiting, difficult feedings, refusal to feed, and lack of weight gain in babies—are often vague, leading many parents and physicians to overlook the possibility of EoE and mistake the condition for GERD, colic, or even behavioral issues. EoE is also frequently dismissed by parents with such explanations as "My son just eats too fast," or "My daughter just doesn't chew carefully." Often, it is only once more serious symptoms appear—symptoms as severe as difficulty swallowing (dysphagia) and food impaction (food becoming lodged in the esophagus)—that doctors finally make a diagnosis of EoE.

To diagnose EoE, Koslowe explains, pediatric gastroenterologists perform an upper-endoscopy biopsy to look at a child's esophageal lining and check for elevated levels of eosinophils, a certain type of white blood cell found in people with both EoE and GERD; a trial of an acid-blocking medication may be prescribed to help differentiate those two conditions. Management of EoE in infants generally involves avoiding known dietary triggers if they can be identified, or trialing an amino-acid formula that virtually eliminates allergic potential from the diet.

Treating EoE in older kids is a bit more challenging, however, since their diets and nutritional needs are far more varied. "Giving a seven- or eight-year-old nothing but an elemental amino-acid formula is not realistic," Koslowe acknowledges. In these cases, if no specific allergic trigger can be identified by the allergist, doctors often suggest the "six-food elimination diet," which cuts out the six most common food allergens: milk, soy, eggs, wheat, peanuts and tree nuts, and seafood. Although this can be a difficult diet for a child to stick to (especially for school-age kids who are surrounded by temptation), the regimen can result in a notable resolution of the disease. "It's also highly recommended that parents consult with a nutritionist before introducing the six-food elimination diet, to ensure that the child still receives adequate nutrition," adds Koslowe.

In addition to elimination diets, there are medical therapies available for older children. These include swallowed steroid therapies, which minimize EoE symptoms by decreasing the number of allergic cells involved in an immune reaction. Originally intended to address inflammation of the lungs and airway caused by other allergic or inflammatory diseases, these medications also have been found to be effective in treating inflammation in the esophagus by swallowing them rather than inhaling them. The most important thing, whether a child is facing EoE or allergic GI disease, is to make the diagnosis. Says Koslowe, "When we do that, we can help kids and families cope."