Research suggests eczema may be associated with gingivitis, toothaches, cavities, and infection. The exact link is not clear, but inflammatory processes, shared developmental pathways, and germ exposure may play a role.

Eczema is a broad term for a group of inflammatory skin conditions with similar core symptoms of itching, discoloration, and irritation. Around 31 million people in the United States have some form of eczema. The most common type of eczema is atopic dermatitis.

Other conditions that occur alongside eczema are called comorbidities, or conditions associated with eczema. While cardiovascular, ocular, and certain mental health disorders are recognized comorbidities in eczema, some research suggests oral health conditions may also have a higher rate of occurrence.

This article explores the association between eczema and oral health and looks at ways to care for oral health while managing eczema.

The relationship between eczema and oral health is not fully understood.

As an inflammatory skin condition, eczema can develop anywhere on the surface of the body, including around the mouth and on the lips.

This type of eczema, known as perioral dermatitis or periorificial dermatitis, can cause irritated, dry, and flaky skin and is a direct way eczema can affect oral health.

Eczema can also have other, less direct effects on oral health, explains Dr. Amy Huang, a board certified dermatologist from Manhattan, New York.

For example, people living with eczema have a higher risk of infections and allergic conditions, which often means they are taking medications that can cause adverse oral side effects.

“Patients with eczema are sometimes on oral antibiotics, which can cause oral yeast infections [in the mouth],” said Huang. “Patients with eczema can also concurrently have asthma, and many patients with asthma rely on steroid inhalers, which can also lead to oral yeast infections.”

However, the link between eczema and oral health goes beyond dry lips and secondary infections. It appears to be bi-directional, meaning oral health can affect eczema just as eczema can affect oral health.

According to a 2020 review, several theories exist on how oral health may affect skin conditions such as eczema.

Innate immune system impairment

Some evidence suggests that exposure to oral bacteria before and after birth may affect how a child’s immune system develops. If the birthing parent has gum disease, it may impair the development of a child’s innate immune system, which includes the development of barriers to infection, such as the skin.

Skin barrier dysfunction is a prominent feature of eczema. It prevents skin from maintaining an optimal level of hydration, resulting in dry skin that is vulnerable to pathogens and irritants.

Underlying immune dysfunction

The second theory linking oral health and eczema suggests that early-life exposure to oral bacteria influences how the future immune system responds to infection, both in the mouth and other areas of the body.

In this theory, the same immune dysfunction that contributes to gum disease contributes to eczema.

Cross-reactivity

Some experts hypothesize that oral infections may lead to skin conditions through cross-reactivity from heat-shock proteins — a type of protein that cells produce under stress.

Human and bacterial cells make heat-shock proteins. According to this theory, heat-shock proteins from mouth bacteria trigger an immune response toward any heart-shock proteins, including those then made by skin cells.

The immune system mistakes the body’s heat-shock proteins for those from the bacteria, creating an inflammatory response in the skin.

While the exact link between eczema and oral health remains unclear, certain oral challenges occur more frequently with eczema than others.

According to the 2020 review, for example, atopic dermatitis is primarily associated with:

  • gingivitis
  • toothaches
  • oral infections

A smaller 2020 study also found an association between atopic dermatitis and dental anomalies, or variations in the typical structure, size, shape, or number of teeth.

The researchers attributed the connection to the shared origins of teeth and skin, which both develop from embryonic tissue known as the ectoderm.

Oral health is important for everyone, but living with eczema may come with unique oral challenges.

For example, eczema can increase infection risk from naturally occurring mouth bacteria and chronic medication use.

In addition, the potential bi-directional link between oral health and eczema suggests that inadequate oral care could have negative effects on eczema symptoms and their management.

To help maintain oral health when living with eczema, Huang recommends brushing and flossing after every meal.

Traditional dental floss may cause injury to the gums and may open them to infection. Therefore, a water flosser — also known as an oral irrigator — can be an effective alternative to removing oral debris.

Beyond these measures, maintaining oral health alongside eczema will depend on individual circumstances and existing oral health concerns.

To rinse or not to rinse

Mouthwash use remains a topic of debate, and deciding if it fits into an oral care routine may require professional input.

According to one 2022 analysis, many mouthwash ingredients are highly variable and unstable in their formulations, and little is known about their efficacy in relation to oral health.

A 2022 review, on the other hand, states scientific evidence continues to support the use of antibacterial mouthwashes for suppressing bacterial adhesion in the mouth.

A dentist or dental specialist can determine whether a person should add mouthwash — and which type — to an oral care routine for eczema.

Maintaining moisture

Saliva plays an important role in preventing infections and tooth decay. It helps wash away debris from eating and contains antimicrobial substances that fight bacterial growth, among other purposes.

Maintaining adequate moisture in the mouth is crucial for natural oral health. One simple and effective way to achieve this is by drinking water regularly.

A population-based panel study from 2021 found drinking less than 1 cup of water a day was associated with a greater prevalence of periodontal disease and dental caries, a broad term describing different presentations of tooth decay, such as cavities.

Managing eczema

Huang advises people to remember managing eczema as a part of oral healthcare. For example, well-managed eczema is less likely to cause mouth and lip irritation and may be less likely to flare due to oral conditions.

Eczema and oral health appear to have a bi-directional relationship, meaning they each potentially affect the other. Eczema may be associated with oral conditions such as gingivitis and dental anomalies, and oral conditions such as gum disease may influence immune responses in eczema.

While the exact reasons for the link between eczema and oral health are not clear, shared developmental pathways, inflammatory responses, and immune function may all play a role.

Managing eczema and focusing on maintaining oral healthcare may benefit both types of conditions.