What is eosinophilic esophagitis and how is it diagnosed?
Eosinophilic esophagitis (EoE) is a condition that has not been recognized for very long, in comparison to many other familiar diagnoses frequently associated with feeding difficulties. In the 1970s, there were cases suggestive of EoE, but not until the 1990s did a physician distinctively identified the disorder and named it EoE (Kelly et al., 1995).
Eosinophils are a type of disease-fighting white blood cell. Their function is to protect the body, to fend off bacteria and parasites and to help kill cells that need to be killed. However, high amounts of eosinophils can cause autoimmune conditions, which develop when the body's immune system decides that healthy cells are foreign and begins to attack them.
Typically, eosinophils exist in the gastrointestinal region, such as in the colon, the duodenum, and the gastric antrum. The esophagus, however, typically does not have eosinophils. It is possible to get some eosinophils from reflux, but that's a different issue. Eosinophils are not supposed to be in the esophagus, and certainly not in the quantity that they are in individuals with EoE.
In the early 1990s, EoE was defined as a distinct clinicopathological diagnosis. In other words, it cannot be diagnosed simply from a pathology study or from a clinical study; both must be conducted. In 2007, a number of gastroenterologists with experience in EoE collaborated and authored a position statement on how to diagnose EoE. They outlined the clinical symptoms of EoE to include: vomiting, abdominal pain, heartburn, dysphagia, reflux symptoms, and avoidance of feeding and eating. In addition, they agreed that the patient must have multiple biopsies of different areas of the esophagus, because it can be worse in certain areas than in others. The researchers also determined that they would evaluate the histology of all other GI tracts to be normal, in order to exclude any other GI diagnoses, as clinically, some of these diagnoses (e.g., GERD, Crohn's disease, etc.) are similar to EoE.
In the mid- to late-2000s, there was a dramatic increase in the amount of research being conducted in the area of EoE. In response to this research, a task force of GIs assembled in 2011 and created a consensus report on EoE. Based on the new research findings, they provided the following definition of EoE: "Eosinophilic esophagitis represents a chronic, immune/antigen mediated, esophageal disease characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation.”
The prevalence of EoE is increasing, which may be due in part to increased awareness and knowledge of the disorder. As of 2004, there were one to two cases in 10,000 documented (Noel et al., 2004). In 2012, four to five cases in 10,000 were documented (Liacouras et al., 2012). It is three times more prevalent in males than females (Furuta et al., 2007).
EoE is a chronic condition: there are ways to manage it, but not to cure it. In addition, there have been multiple reports of familial clustering with EoE (i.e., the occurrence of EoE within some families is greater than what would be expected from the occurrence in the general population).
Most patients with EoE will have about four to five foods to which they're responsive on the skin prick test. However, up to 25% of patients with EoE will have severe food allergies. When food allergy is defined as a food sensitivity, about 70% of children with EoE will have a skin-prick positivity to food, whereas 50 to 60% of adults with EoE will have a skin-prick positivity to food. When food allergy is defined in relation to outcome, if problem foods are removed from a person's diet, 50% to 70% of people see improvement in their endoscopy results, as well as their quality of life. The foods that are most frequently implicated in children include (but are not limited to) the following: eggs, cow's milk, soy, wheat, corn, peanuts, tree nuts, shellfish, fish, beef and rye.
In addition to foods, aeroallergens such as pollen and spores can be triggers in EoE, but to a lesser degree. Some findings have suggested that aspergillus/dust mites can result in eosinophils in the esophagus, as some individuals have EoE during pollen season. According to some case reports, immunotherapy for aeroallergens has been shown to improve EoE symptoms.
Some commonly occurring symptoms of EoE in infants include:
- Refusal to feed
- Failure to thrive
- Feeding intolerance
- Food/Oral aversion
In older children with EoE, we are likely to see:
- Abdominal pain
- Food refusal
- Food aversion
If EoE is not detected early enough, narrowing of the esophagus can occur. This may cause a child not to want to advance to eating more solid foods, because they feel like they have a big lump in the middle of their throat, which makes swallowing very uncomfortable. We certainly don't want our developing children to be faced with these types of symptoms that can negatively impact learning to eat, as well as the enjoyment of food and the social aspect of feeding.
Please refer to the SpeechPathology.com course, Eosinophilic Esophagitis: Introduction and Implications for Feeding, for more in-depth information on the diagnosis of Eosinophilic Esophagitis (EoE) and its implications for treatment of developing feeders.