Eczema treatment may cut serious infection risk

Children with eczema are more likely to develop serious bone and joint infections, and treating the skin condition could help reduce that risk, a new study finds.

These sometimes life-threatening infections can leave children seriously ill and hospitalised for weeks.

The University of Auckland research identifies eczema as the first potentially preventable risk factor for childhood bone and joint infections, a condition for which New Zealand has the second-highest rate in the world, says lead author Sarah Hunter.

Researchers interviewed more than 400 children and their families in the largest interview-based study of its kind. They found children with eczema faced about three times the risk of developing a bone or joint infection compared with children without eczema, even after accounting for factors such as household income and crowding, and access to healthcare. Children receiving treatment for eczema had no increased risk.

Hunter, an orthopaedic surgery trainee candidate who is undertaking further doctoral studies at Waipapa Taumata Rau, University of Auckland, says the findings provide the first clear opportunity to reduce the risk of these infections.

The study compared children with eczema who had been hospitalised with bone and joint infections with children who had never experienced a bone or joint infection.

Working with research nurses from the same ethnic backgrounds as participating families, the team collected information not routinely captured in medical records, including barriers to healthcare, housing conditions, socioeconomic factors and eczema treatment.

Hunter says the study provides answers to questions clinicians are regularly asked by concerned parents.

“Families often ask how they can prevent it from happening again, or whether they did something wrong. Until now, we haven’t had many answers. But for some children at least, we can now say, ‘let’s get your eczema treated, let’s make sure siblings with eczema are treated too, and help lower the risk for the whole family’.”

The findings also challenge some long-held assumptions about what puts children at risk of the disease. Household crowding was reported by about 30 percent of both children who had experienced infections and those who had not, suggesting it was not a distinguishing risk factor in this study.

Māori and Pacific children continue to experience disproportionately high rates of bone and joint infections, says Hunter. Previous research by her team found rates of 25 cases per 100,000 Māori children and 38 per 100,000 Pacific children, compared with 17 per 100,000 New Zealand European children.

The new study found eczema emerged as a strong risk factor for disease, particularly for Māori and Pacific children.

“Household crowding did not emerge as a significant risk factor. While it may contribute to infection risk, eczema was much more strongly associated with these infections in our study,” she says.

The study also highlighted broader challenges facing many families. More than 30 percent of participants reported at least one barrier to accessing primary healthcare during the previous month.

Hunter says the findings suggest eczema treatment may do much more than relieve an uncomfortable skin condition.

"We can now give families that information so they can make informed decisions about managing eczema proactively," she says.

Bone and joint infections can have devastating consequences for children and their families. In severe cases, children can spend up to 70 days in hospital, undergo multiple operations and require four to six weeks of antibiotic treatment. Around five to ten percent experience long-term complications, including impaired bone growth, chronic infection, ongoing pain and joint stiffness.

Treating bone and joint infections also carries a substantial economic cost. Separate research by Hunter's team found some families incurred costs running into the tens of thousands of dollars through lost income, travel and accommodation while caring for a sick child.

The impact is also felt across the health system, she says.

“People don't always realise how serious these infections can be. The most expensive admission we saw in recent years cost the health system about $3 million for one child.”

Hunter says families who participated in the study played a crucial role in helping researchers understand the disease.

“There was a real sense of desperation among families whose children had become seriously ill, and a strong desire to understand why it had happened. Among families who hadn’t experienced these infections, there was a real willingness to contribute to research that could improve outcomes for children in their communities.”

The University is now working with the Child and Youth Clinical Eczema Network to encourage earlier treatment of eczema through primary care. Hunter is also continuing research into severe childhood infections during a six-month Fulbright-supported placement at Vanderbilt University in Nashville, where researchers are investigating why some children are more vulnerable to serious infections and how those risks can be reduced.

“We’re facing a unique challenge that no one has solved yet,” she says. “The chance to work together across countries to find solutions is incredibly exciting.”

New Zealand also has high rates of bone and joint infections in adults, although other conditions, such as diabetes, increase their risk of infection, she says.

• Read the study