HOW ALLERGIES ARE RELATED TO THE GUT

Allergies can cause a number of other diseases. At the same time, one of the organs that suffers significantly due to allergies is the gastrointestinal tract.

Gastroenteritis, irritable bowel syndrome, stomatitis, reflux disease… this is just an incomplete list of possible diseases that develop against or precede allergies.

What links gastrointestinal disorders to food allergies is that most immune cells are concentrated in the gut. Cells that produce antibodies to neutralize allergens they perceive as a threat are also abundant in the gut. Given that food contains many substances that can trigger an immune response, the digestive tract becomes a typical site for the development of allergies.

It has also been proven that patients with birch pollen allergy have clear signs of long-term allergic inflammation of the intestinal mucosa, which intensifies during the pollen season.

ORAL ALLERGIC SYNDROME

Or oral allergy syndrome (OSA) is a collection of symptoms that manifest in the oral cavity. They appear in patients with hay fever after eating certain fruits and vegetables. This is one of the most common links between allergies and digestive symptoms.

There is evidence that OSA affects about 8% of children and 5% of adults with inhalant allergies. As already noted, people with an allergy to birch pollen most often have OSA. Due to the similarity of the main allergen of this pollen to food allergens, symptoms can appear after eating apple, cherry, pear, as well as celery, carrots, hazelnuts, soy or peanuts.

This condition is characterized by symptoms such as swelling, itching, redness and / or burning of the mucous membrane of the mouth and throat.

However, in 2-10% of patients with OSA, in addition to the local symptoms mentioned, systemic reactions from other organs may also occur, and anaphylactic shock may develop in 1.7%.

It is believed that the occurrence of OSA symptoms after eating boiled or baked vegetables or fruits may indicate the potential for systemic reactions. After all, most people with OSA can tolerate heat-treated foods.

irritable bowel syndrome

Another common condition closely associated with the development of allergies is irritable bowel syndrome (IBS).

By this disease, as a rule, they mean a group of gastrointestinal symptoms that usually appear together. IBS can be identified, for example, by occasional abdominal pain or discomfort due to irregular stools.

According to various estimates, 5.2-22% of the world’s population may suffer from this condition. Of these, 5–50% may also have an undiagnosed food allergy.

A 2015 study showed that among 512 patients with irritable bowel syndrome, the proportion of patients with food allergies was 43.5%.

A 2006 study indicates that 70% of patients with IBS had food-related symptoms, and that 62% of them improved their symptoms after eliminating or reducing certain foods.

In 2008, scientists proposed the term “atopic IBS” to describe a new subtype of IBS associated with allergic diseases. They reported that the prevalence of IBS compared with the general population was significantly higher in patients with allergic rhinitis and allergic dermatitis. According to some estimates – 2.67 and 3.2 times, respectively. Although these numbers may vary. For example, a Taiwanese study found that children with allergic dermatitis (AD) had a 1.45 times higher risk of developing irritable bowel syndrome than children without AD.

Other studies also point to a direct relationship between IBS and the severity of allergic reactions, as well as between IBS and air quality. In particular, according to another Taiwanese study (254,207 children under 18 years of age), the number of newly diagnosed cases of IBS was directly associated with an increase in air concentrations of carbon monoxide, non-methane hydrocarbons, nitrogen dioxide and methane – common components of urban smog.

And in a meta-analysis of 12 cohort studies in Europe and North America, increased exposure to nitrogen dioxide and particulate matter was found to be associated with an increase in asthma.

Another study found that the more allergic problems a child under 12 had (such as asthma, rhinitis, eczema, and food allergies), the greater their risk of stomach pain.

One of the factors explaining the link between allergies and gastrointestinal problems is the gut microbiota.

Patients with IBS and allergic diseases are known to show changes in the composition of the gut microbiome , including an increase in Firmicutes bacteria and a decrease in Bacteroides with a decrease in members of the genus Bifidobacterium . In particular, Bifidobacterium longum were found in only 11.1% of children with allergies compared to 30.3% of healthy children.

RECURRENT APHTHOSIS STOMATITIS (RAS)

This is a disease of the oral mucosa, which consists in the periodic occurrence of erosions surrounded by inflamed mucosa. This is a fairly common disease. For example, in Poland, 11–30% of the population may have it.

It is assumed that the formation of aphthae is influenced by genetic factors, stress, trauma, bacteria, viruses, hormonal disorders, as well as a lack of trace elements iron ( Fe ), zinc ( Zn ) and selenium ( Se ) and a deficiency of B vitamins, in particular B ₁₂ and folic. acids. Diseases of the digestive tract can also cause aphthous stomatitis, in particular, celiac disease, Crohn’s disease, ulcerative colitis, Behcet’s disease and food allergies (mainly to milk, nuts, tomatoes, citrus fruits and coffee).

For example, in a Swedish study of 27 patients with recurrent aphthous stomatitis, 12 had food allergies.

A 2007 Turkish study of 27 patients found that food allergies could be responsible for 35–50% of aphthae, and improvement after an elimination diet was observed in 75% of patients.

In a Chinese study published in 2017, among 128 patients with severe aphthous stomatitis, 17 (13.3%) had food allergies. The most common allergens were milk, eggs, seafood, wheat flour, fish and soy.

REFLUX DISEASE FOR ALLERGIC CAUSES

Reflux disease is the discharge of gastric contents into the esophagus, causing unpleasant symptoms and specific complications.

There are primary reflux, which occurs due to congenital disorders in the structure of the lower esophageal sphincter, and secondary. The latter is associated with systemic diseases, including food allergies.

It is believed that reflux disease affects 3-10% of the world’s population.

The association between reflux disease and food allergy is especially pronounced among children under 3 years of age and is estimated to be about 40% in this group.

The main allergen that can provoke reflux disease is cow’s milk protein. But actually diagnosing this disease can be problematic precisely because of the similarity of its symptoms with the symptoms of a milk allergy.

ALLERGIC REACTIONS FROM THE STOMACH

Young children most often suffer from this problem, and the already mentioned cow’s milk is the main cause.

Such allergic reactions can affect about 1% of babies and occur as acute or chronic inflammatory conditions.

An acute allergic reaction of the gastric mucosa is usually caused by cow’s milk and chicken egg allergens. A few minutes after ingestion of allergenic food, the motor activity of the stomach increases, severe contractile pains in the abdomen, and vomiting appear. Then edema and congestion of the mucosa develop, bloody petechiae appear, as a result of which inflammation develops, affecting, in particular, the antrum of the stomach.

If the disease becomes chronic, symptoms characteristic of an allergic background, as a rule, are not observed. Instead, there may be a feeling of fullness, flatulence, abdominal pain, loss of appetite, and impaired stools.

ACIDOPHILIAN GASTROENTERITIS

This is a fairly rare disease that very often occurs with concomitant allergic problems.

For example, 50–75% of patients so diagnosed have evidence of atopy . And 90% note a decrease in symptoms after an elimination diet and / or elimination of them as a result of steroid therapy.

The frequency of this disease is estimated at 1-10 cases per 100,000 patients.

Characteristic signs of acidophilic gastroenteritis are the presence of gastrointestinal symptoms, eosinophilic infiltrates in the gastrointestinal tract, eosinophilia . At the same time, no pathological damage to other organs is observed.

EOSINOPHILIC ESOPHAGITIS, GASTROENTERITIS AND COLITIS

Eosinophilic esophagitis is considered as a specific form of food allergy. Over the past 30 years, the prevalence of this disease has increased tenfold.

In young children, the disease is manifested by feeding and growth problems, in older children and adults, swallowing disorders and episodes of food jamming dominate. Diagnosis is based on histological examination of the esophageal mucosa.

Eosinophilic esophagitis is treated with an elimination diet and pharmacotherapy.

is an extremely rare disease that affects both adults and children. The frequency of its occurrence is estimated at about 1 case per 100,000 patients.

Signs of eosinophilic gastroenteritis, occurring in almost half of patients, are abdominal pain, vomiting, and diarrhea. Two-thirds of patients have eosinophilia , an elevated level of eosinophils in the blood.

In children, eosinophilic gastroenteritis is closely associated with food allergies, and comorbid atopic diseases or a family history of allergies are detected in 50-70% of cases.

Eosinophilic colitis is another rare disease. Children most often suffer from it. For example, in infants, this type of colitis is most commonly induced by an allergic reaction dependent on cow’s milk protein or soy, although cases have also been described in breastfed infants.

Treatment for EC depends on the age of the patient. It is usually enough to eliminate the causative allergenic factor (cow’s milk protein or products containing soy) from the diet of children and this will lead to the elimination of clinical symptoms within 72 hours.