This is one of the most common questions that I get asked in the office. Allergic diseases are certainly becoming more and more prevalent in the developed world. General pediatricians and specialists are on ‘high-alert’ for this when evaluating a child that may be sick. Within the realm of intestinal diseases, however, a true allergy is actually not very common. To understand this, we must first understand what ‘allergy’ means.
An allergy is a biologic response from our body’s immune system. When our body senses a foreign invader, our army of immune cells attacks it. It does this by releasing chemicals into the blood stream and/or in to the organs where the threat may lie. Those chemicals are meant to destroy the invader, but often hurt our healthy organs as well. For example, airborn pollen may land in your eye, the immune system senses that pollen, releases those chemicals, and as a consequence we get itchy, puffy, watery eyes. The same thing can happen in the bowel if we ingest food that we are allergic to.
Intestinal manifestations of food allergies
One of the more common sites of an allergic response to food is in the esophagus—the food pipe. When the esophagus gets inflamed, it can manifest in a few different ways: heartburn symptoms, chest pain, chronic dry cough, upper abdominal pain, frequent regurgitation, or food that is stuck the chest. The name of this is Eosinophilic Esophagitis. Food allergies lower in the bowels can cause diarrhea, blood in the stool, abdominal pain, weight loss, anemia, and fatigue.
There are usually other red flags
One of the most important things to remember is that intestinal manifestations of allergy almost NEVER happen alone. In other words, if your concerns are isolated to common belly complaints (pain, nausea, excessive gas, constipation), rarely will this be a true “allergy” requiring removal of specific foods. There are almost always other red flags that are classically seen with allergies (rashes/hives after eating, weight loss, wheezing or respiratory trouble after eating, throat tingling or swelling after eating).
Allergy vs. insensitivity
By contrast, insensitivity to food is something that doctors do not fully understand but is clearly not an allergic process. Many parents are adamant that their child feels bad after eating certain foods. Often children are bloated, have pain, exhibit negative behavior, or have diarrhea after eating certain foods. The key is to distinguish a biological process like an allergic reaction from insensitivity. Often, with the latter, careful reduction of a food item (as opposed to complete elimination of that food) may help your child feel better.
Where to start?
We recommend a careful history and physical exam with your general practitioner to start. They will often ask a pediatric gastroenterologist like me, an allergist, and/or a dietician to help them figure out what is going on. At the end of the day, we ONLY want to ask a kid to remove a food from their diet if absolutely necessary. It can greatly affect a child’s quality of life if their food choices are limited. Allow your team of physicians some time to be thoughtful about a treatment plan before proceeding with food eliminations.