There may be a link between antibiotics and eczema. There is a strong genetic component to eczema, but rising case numbers in recent decades suggest external factors may also contribute to the development of eczema in significant ways.

Eczema is a chronic inflammatory condition. It results from a combination of genetic, immune, and environmental factors. The immune system overreacts to environmental irritants and allergens in people with eczema.

Given the role of inflammation in eczema, factors that affect the development of the immune system in early childhood, including the use of antibiotics, have been of particular interest to experts.

This article examines how antibiotics can affect the developing immune system and how this might influence a person’s risk of eczema in the future.

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The microbiome is the collection of bacteria, viruses, and other microorganisms that live in and on the body. It includes bacteria in the gut as well as those on the skin.

A well-balanced microbiome provides a variety of health benefits by:

  • supporting digestion
  • providing essential vitamins and amino acids
  • preventing the overgrowth of harmful microbes
  • stimulating the development of the immune system

The microbiome helps support immune development by training the immune system to distinguish the disease-causing microbes that can cause health conditions from the beneficial ones that support human health.

Disruption of the microbiome ecosystem, particularly early in life, can interrupt this training process and make it difficult for the immune system to recognize the microbes.

Antibiotic use, for example, can disrupt essential interactions between the microbiome and the immune system by killing healthy bacteria in the gut and on the skin. In turn, this leads to the development of abnormal immune responses.

As a result, the immune system reacts to the normal microflora of the gut or skin, leading to chronic inflammation.

Researchers have linked exposure to antibiotics to inflammation that contributes to a variety of health conditions, including allergies and autoimmune diseases.

Exposure in the first 2 years of life

Overall, most studies suggest an association between antibiotic use and eczema.

According to a 2017 analysis of 34 clinical studies spanning the last 6 decades, children exposed to antibiotics within the first 2 years of life were 26% more likely to develop eczema than those without exposure.

Exposure in the first year of life

A 2021 study involving more than 700,000 children from Sweden found that children exposed to antibiotics during the first year of life were 52% more likely to develop eczema than other children.

Exposure during pregnancy

Not all studies have seen the same association between eczema and antibiotic use. Others suggest there may be more to the relationship. For example, some studies suggest the timing of antibiotic use may be important.

A 2019 review looked at seven studies that examined antibiotic exposure during specific intervals throughout pregnancy.

Researchers found that although prenatal exposure did increase the likelihood of developing eczema, antibiotic use during the third trimester did not affect eczema risk.

Genetics

Underlying genetics or familial factors likely play a role as well. Many studies that have identified a relationship between antibiotic use and eczema have found that this relationship becomes attenuated or completely lost in sibling pairs.

These findings suggest there may be one or more underlying factors that affect several family members and increase the likelihood of both eczema and infections that require antibiotics.

Genetics are likely to play a role in moderating this dual effect.

A 2021 study found that, among nearly 600 children in China, those with a genetic mutation in an immune-related gene were over three times more likely to develop eczema after antibiotic use than those without the mutation.

Therefore, an increased risk of eczema may not be a direct result of antibiotic use but the result of some other trigger that also increases the risk of infections.

If eczema is the result of gut microbiome dysregulation, some experts have suggested that the use of probiotics may help control symptoms of eczema.

However, a 2018 analysis of 39 clinical trials found no association between the use of probiotics and improvement of symptoms in people with established eczema.

Additionally, in a 2017 trial of infants at high risk of developing eczema, the use of a probiotic during the first 6 months of life did not decrease the likelihood of developing eczema by 2 years of age.

Although current evidence suggests probiotics are unlikely to affect a person’s risk of eczema, studies have not directly examined the use of probiotics after antibiotic use.

Some research does suggest that probiotics may help prevent other antibiotic-associated conditions in infants, though. More research is necessary to define this relationship.

Probiotics are not a risk-free treatment. It is best to consult a doctor before taking them, particularly for young children.

Here are some frequently asked questions about eczema.

What things cause eczema to flare up?

Common triggers for eczema include dry skin, contact with irritants, and emotional stress.

Recognizing triggers and taking steps to manage or avoid them can help reduce the frequency or severity of eczema flare-ups.

Can a bacterial infection trigger eczema?

Having eczema may increase a person’s risk of Staphylococcus aureus infection. It can cause symptoms such as weeping and crusting on the skin. As the infection irritates the skin, it may worsen symptoms of eczema.

What antibiotic is good for eczema flare-ups?

If a person with eczema develops a bacterial infection on the skin, medical professionals may recommend either topical antibiotics, such as fusidic acid, or an oral antibiotic, such as flucloxacillin.

However, there is limited evidence that these treatments are helpful.

Eczema occurs due to a variety of internal and external factors that result in immune dysregulation and contribute to chronic inflammation.

Antibiotic use early in life may disrupt the development of the immune system and increase the likelihood of developing eczema. Other factors, such as genetics, likely modulate these effects as well.

If children who already have an increased risk of eczema or other allergic conditions are exposed to antibiotics, their parents or caregivers can contact a doctor about how to reduce the risk of eczema developing.