Eosinophilic Oesophagitis (EoE)

EoE is a rare allergic condition that effects the oesophagus (food pipe), that affects approximately 50 per 100,000 children. This condition is known to be more prevalent in males and is associated with other allergic disorders such as immediate food allergy, atopic dermatitis, eczema, asthma and allergic rhinitis. It is more common in children with a previous history of oesophageal atresia.

In EoE, eosinophils (a type of white blood cell) that can be found in the oesophagus (food pipe) and cause inflammation in this area. This type of white blood cell is not usually found in this location and can be raised for several reasons – for which you child will have been investigated for.

For those subsequently diagnosed with EoE, if left untreated, the inflammation can lead to narrowing of the food pipe (strictures) or significant symptoms of difficulty swallowing. If a stricture occurs, it may require surgery to open the narrowing of the food pipe (dilatation). If treated effectively, then symptoms or risks of stricturing of the oesophagus can be reduced.

Symptoms can vary from one person to another and depend on the individual’s age. In children, EoE often present with some or all the following symptoms:

• feeding aversion or difficulties
• poor growth
• vomiting
• reflux
• abdominal pain or distension
• lengthy mealtimes
• avoiding difficult textures (meat and bread)
• food impaction or difficulty swallowing

The medical word for this type of swallowing difficulty is dysphagia, patients with EoE often report the feeling of food travelling more slowly down when swallowed or getting stuck (usually) in the chest, often intermittent but sometimes with every swallow. The sensation of food sticking can range from mild, making eating difficult/uncomfortable to severe and very distressing. It can occur without pain or with significant pain.

Unfortunately, in this condition, symptoms do not always correlate with disease activity and therefore cannot be used alone to diagnose EoE or to guide if the condition is in remission. Repeat endoscopies are often required following a treatment change or for surveillance.

EoE can only be diagnosed by taking a tissue sample (biopsy) from the oesophagus (food pipe) during an upper gastro-intestinal endoscopy (camera test). The gastroenterologist (gut doctor) will take a minimum of 6 biopsies at varying sites down the oesophagus (food pipe). The tissue samples taken, are then analysed to count the number of eosinophils (type of white blood cell) present; this is referred to as the eosinophil count. This procedure is usually performed under a general anaesthetic.

If the eosinophil count is greater than 15 per high power field a standardised area under the microscope ( around 0.3mm2), with some other associated changes, the diagnosis of EoE is made.

Currently there is not a less invasive technique for the diagnosis of this condition. But techniques such as awake nasal endoscopy are being explored for the future.

Once the diagnosis is made and a treatment is started, your child will need another endoscopy to assess response. It is helpful for the family to keep a log of symptoms such as food impaction or swallowing difficulties in between endoscopies, as part of the re-assessment.

The cause of EoE is not fully understood, although it is found to be triggered by certain food proteins. Atopic conditions such as eczema, rhinitis and asthma are more common in EoE compared to the general population. It is not yet known if atopy is a predisposing factor in EoE.

This type of allergy is non-IgE mediated or delayed in nature and although we know it involved the immune system, the full understanding of this type of allergy is ongoing. Unlike IgE-mediated or immediate allergies; allergy tests such as skin prick tests (SPT) or specific IgE blood tests (sIgE) are unhelpful to guide food exclusions in this condition.

There are six food proteins that are common triggers in EoE, these include, milk, egg, wheat and gluten containing grains, soya, seafood and nuts or seeds (peanut and tree nut), however this does not mean that in all cases, all of these foods will need to be excluded long term.

EoE is a chronic (long term) condition were symptoms will wax and wane. Currently there is no cure for this condition, although there are treatments that are successful to keep it under control. Your consultant gastroenterologist will discuss these treatment options with you in detail and help you make an informed decision about which treatment would be best suited to your child.

There are three main treatments used in EoE, each aim to improve symptoms and reduce the inflammation in the oesophagus (food pipe). The three treatment options are discussed below:

1.Proton Pump Inhibitors (PPI’s)

PPI medications are often used to treat symptoms of acid reflux or heartburn, and although EoE is not caused by reflux, these medications can also be helpful.

2.Dietary manipulations

Note: Do not start an exclusion diet unless advised by your gastroenterologist or allergy dietitian

Exclusion diets

As mentioned above we know that EoE can be triggered by certain food proteins; the main triggers being milk, egg, wheat and gluten, soya, fish and shellfish, and nuts (peanut and treenut). Dietary treatment of EoE requires careful avoidance of one to six (or more foods) and repeated endoscopies to determine which food protein is the trigger, so that a long-term plan can be reached.

We use a ‘step-up’ approach, usually starting with a one or two food exclusion diet (FED), usually milk plus or minus gluten, then 4FED (milk, egg, gluten, soya) and then 6FED (milk , egg, gluten, soya, seafood and nuts or seeds).

During this process, careful attention to nutrition with the help of a dietitian, expert in EoE, is needed is essential as these diets can have a high success rate, but they can be difficult to adhere to in the long term.

Elemental diet

In rare cases we may suggest an elemental diet (completely liquid using a specialised formula). We only recommend this treatment if no response is seen with a 6-food exclusion, and no other triggers have been identified. An alternative would be management with medications.

This specialised formula can be difficult to drink in adequate volumes due to its poor taste. If so, a nasal gastric tube (NGT), a tube inserted from nose to stomach, maybe required to enable your child to consume enough to meet their nutritional requirements.

Also, the negative impact on the quality of life when abstaining from all kind of normal eating, for example social and emotional impact on the patient and their family must be considered.

3.Topical swallowed steroid

There are two topical steroids that are used to treat EoE - budesonide and fluticasone. Both these steroids are swallowed and provide a protective coat for the oesophagus (food pipe). You could think of it like putting cream on eczema.

Budesonide

Budesonide is available in many forms, but for EoE it is given orally (by mouth) so it can coat inflamed tissue in the food pipe, similar to putting cream on inflamed skin. However, for younger children it is not readily available in a suitable form, so we teach you to make the medicine into a sloppy mixture for your child to swallow. When it is made into this mixture it is called oral viscous budesonide (OVB). Our allergy nurse will be able to provide a separate information sheet which explains all about OVB.

For children over the age of 18, there is also a melt-in-the-mouth (oro-dispersible) budesonide tablet that you dissolve on the tip of the tongue. Please speak to your team if you would like to know more about this form of the medication.

Fluticasone

Is a type of medication that is commonly used to help control symptoms of asthma. This is administered via an asthma style pump (inhaler), which is instead squirted into the cheek and then swallowed, rather than inhaled.

Whichever medication is used to treat the EoE (OVB or fluticasone), once administered the medication should not be washed off (by brushing teeth, eating or drinking) for as long as possible (but at least 30-60 minutes). It is often a good idea to take this just before going to bed. We will monitor for side-effects, but these treatments are considered safe and effective. Some children can suffer from oral thrush (candidiasis), due to this medication. Please inform your team should this happen.

You will regularly see your team in clinic (either virtually on video or telephone or in a face to face clinic), however if you need to contact them between appointments, below are some helpful contact details:

The service would recommend the myGOSH instant messaging as the first line of contact with the team, however if your query is urgent, please contact via one of the following telephone number.

• Allergy Clinical Nurse Specialist – 020 7405 9200 ext.1872
• Pharmacy Medicines Information (Monday to Friday from 9am to 5pm) – 020 7829 8608
• GOSH Switchboard – 020 7405 9200 (Ask for the gastroenterology secretaries)