New research has found that use of antibiotics in early childhood may increase the risk of developing eczema by up to 40%.

The study, published in the British Journal of Dermatology, showed that children with eczema are more likely to have been treated with antibiotics in their first year of life.

The research also revealed that each additional course of antibiotics may increase the risk of eczema by a further 7%.

The researchers, from Guy’s and St Thomas’ NHS Foundation Trust, King’s College London, the Aberdeen Royal Infirmary and the University of Nottingham in the UK, analyzed data from 20 separate studies involving children and young adults aged up to 25.

The studies looked at exposure to antibiotics before birth and up to one year after, and the subsequent development of eczema.

It was found that infants are more likely to develop eczema if they had antibiotics within their first year of life, but not prenatally.

One study author, Dr Teresa Tsakok of Guy’s and St Thomas’ says: “One potential explanation is that broad-spectrum antibiotics alter the gut microflora and that this in turn affects the maturing immune system in a way that promotes allergic disease development.”

Dr Carsten Flohr, the paper’s senior author said:

A better understanding of the complex relationship between antibiotic use and allergic disease is a priority for clinicians and health policymakers alike…

“Determination of a true link between antibiotic use and eczema would have far-reaching clinical and public health implications.”

Eczema is a chronic inflammatory skin disease, described as a persistent inflammation of the epidermis.

Atopic eczema is the most common form of the disease and mainly affects children, but can follow on later in life or even develop in adulthood. Around 80% of atopic eczema cases develop by 5 years of age, many occurring by the age of one.

Some experts believe eczema is a genetically inherited condition. In 2006, experts on genetic skin disorders led by the University of Dundee discovered the gene responsible for atopic eczema.

A study published in the journal BMC Microbiology, revealed that the types of bacteria found in the guts of children who have eczema appeared more typical of bacteria found in the guts of adults without the disease.

According to Nina Goad of the British Association of Dermatologists, eczema is the UK’s most common skin disease, affecting 1 in 5 children. She adds that eczema and other allergic diseases have increased over the years, especially for children in high-income countries, but she says the reasons for this are not fully understood.

Goad says:

“The evidence is not conclusive and the researchers are not suggesting that parents should withhold antibiotics from children when doctors feel such treatment is necessary, but studies like this give an insight into possible avoidable causes and may help to guide medical practice.”