Several studies have shown a link between constipation and eczema, though the link is not entirely understood.
Eczema, commonly referred to as atopic dermatitis, is caused by inflammation and skin barrier dysfunction, which leads to dryness, itchiness, and irritation.
However, symptoms of eczema are often more than skin deep. Inflammation in eczema can cause — or be caused by — other conditions that affect different organs in the body.
In particular, a growing amount of research has found a close relationship between the digestive tract and the skin, known as the
As a result, some people with eczema may also experience digestive issues, including constipation.
Several studies have found a link between constipation and eczema.
In a study involving over 170,000 people from Taiwan, people who experienced constipation were more than
There are similar results in a study involving more than 23,000 people from the United Kingdom. In this study, people with constipation were also more than
However, it is not clear whether people with eczema are more prone to constipation.
The skin and the lining of the gut both fundamentally act as a first line of defense against allergens and pathogens from the environment. Both the skin and the lining of the gut are exposed to billions of microbes every day.
When the barrier between the inside and outside world is compromised, such as in eczema, exposure to pathogens and allergens can cause inflammation and irritation, along with other symptoms.
The same thing can happen in the gut. Constipation can cause and be due to changes to the gut microbiome — the collection of bacteria and viruses living in the digestive tract — as well as inflammation and irritation in the gut lining.
Both of these factors can affect the epithelial barrier in the digestive tract, exposing the body to a variety of allergens and pathogens. A “leaky gut” can cause widespread inflammation in the body, including in the skin.
Similarly, inflammation in eczematic skin can spread throughout the body and affect other organs. Inflammatory molecules and immune cells can circulate through the bloodstream and affect the digestive system, leading to inflammation that can affect gut health.
In this way, the signals sent along the gut-skin axis are bidirectional. Changes in one part of the body can affect the other and vice versa. This means that both gut and skin health are related, and when something goes wrong with one, the other can also be negatively affected.
Food sensitivities and allergies are common in people with eczema. In some cases, these sensitivities may also lead to digestive issues as well as skin symptoms.
As a result, many people believe that elimination diets that exclude common food allergens can universally help relieve eczema symptoms, both in the skin and in the gut.
However, 2021 research suggests that a blanket elimination diet will not be effective for most people with eczema. Dietary management of eczema requires medical allergy testing and carefully monitored elimination trials to determine if there is an effect.
However, even in cases where these kinds of trials occur, most people have relatively small improvements in eczema symptoms.
If someone has eczema and constipation, their healthcare team can help them manage their symptoms using lifestyle changes and medication. A medical professional may recommend a multidisciplinary approach involving both a gastroenterologist and a dermatologist.
A dermatologist can also help adjust medications if necessary, since some eczema medications can cause digestive issues.
Eczema may also link to other digestive issues. In one study, children with eczema were
Another older study found that digestive symptoms among children with eczema, including diarrhea, vomiting, and regurgitation, were more common than in those without eczema. These symptoms were mostly mild, but up to
In addition to eczema, constipation has an association with other allergic conditions. In the U.K. study described above, people who experienced constipation were also more likely to have hay fever or allergic conjunctivitis. There was no link with asthma.
They were also more likely than people without digestive issues to experience depression and anxiety.
The health of the skin and the gut are closely related, and people with digestive issues such as constipation may be more likely to develop skin conditions such as eczema.
Although sometimes recommended, evidence suggests that strict elimination diets or probiotics do not usually help relieve symptoms of either constipation or eczema.
If someone with eczema is experiencing digestive issues, their dermatologist, with the help of a gastroenterologist, may be able to provide relief with lifestyle changes and medication.