People with mild or moderate eczema may gain some relief by adjusting their diets, but there are important downsides to consider, McMaster researcher Derek Chu warns.

Fifty per cent of people with atopic dermatitis, commonly referred to as eczema, improved their symptoms when they eliminated certain foods — like dairy products — and continued their other eczema treatments, Chu’s international research team found.

However, 41 per cent of people with eczema saw their condition improve when they continued standard treatments without any dietary adjustment.

The researchers reviewed the data from 10 randomized patient trials involving nearly 600 people, as well as consulting with both patients and their caregivers. The patients with eczema included children and adults.

The study was published in the Journal of Allergy and Clinical Immunology: In Practice.

“My advice to anyone with AD-type eczema is that if you’re going to pursue this dietary option, make sure you keep using your usual medicated creams, moisturizers, and talk to your doctor first,” said Chu, an assistant professor of medicine in the Faculty of Health Sciences.

“Almost all patients going through eczema will consider a dietary strategy and they now have some hard evidence to hang their hat on. Our data show that going on a diet will not be game-changing for eczema; it may modestly improve it but diets also have important downsides.”

Paul Oykhman, first author of the study and an assistant clinical professor at McMaster, added, “With our data, patients, caregivers, and clinicians are no longer left guessing about the outlook with or without pursuing a diet for eczema and can now have an informed conversation together.”

AD, the most common type of eczema, affects an estimated 10 to 15 per cent of Canadians, according to the Eczema Society of Canada.

The research will result in changes to the guidelines on AD treatment, which will include encouraging doctors to discuss the balance of benefits and harms, as well as patient values and preferences, when encountering the topic of diets for eczema, Chu said. Many doctors had previously been reluctant to discuss dietary changes with patients, he said.

However, patients must carefully consider the benefits of eliminating certain foods from their diet, as this may increase the risk of developing potentially life-threatening food allergies and malnutrition, Chu warned.

External funding for the study was provided by the American Academy of Asthma, Allergy and Immunology and the American College of Asthma, Allergy and Immunology.