The study provides a blueprint for improving future bleach bath studies.
Jonathan Silverberg, MD, PhD, MPH
According to a new study from Northwestern Medicine, a water bath is as effective as a bleach bath in soothing and reducing symptoms of atopic dermatitis (eczema) in children and adults.
Published in Annals of Allergy, Asthma and Immunology on Nov. 13, the study was a systematic review and meta-analysis of all available studies comparing bleach and water baths (a total of 4 studies). The collective results indicated that water baths are as effective as bleach baths for reducing the severity, visibility and extent of atopic dermatitis and bacterial infection (such as Staphylococcus aureus). Patient symptoms were evaluated at 4 weeks and compared with baseline for the Eczema Area and Severity Index (I2 = 98%; random effect regression model, P = .16) or body surface area (I2 = 96%; P = .36).
"I don't know if it throws the baby out with the bathwater, but bleach baths lack the evidence to support how commonly they are being recommended," said senior author Jonathan Silverberg, MD, PhD, MPH, assistant professor of dermatology at Northwestern University Feinberg School of Medicine, dermatologist at Northwestern Medicine, and director of Northwestern Medicine's Multidisciplinary Eczema Center.
"The water baths appear to be doing most of the heavy lifting,” Silverberg continued. “If bleach is adding any benefit, it's quite modest.”
Silverberg said many atopic dermatitis patients fear any type of bathing will dry their skin, but these study results should reassure them that bathing regularly is perfectly safe.
A bleach bath uses a small amount of bleach mixed into a full bath of warm or cool water. It’s common for dermatologists to recommend patients that submerge themselves in the bleach bath from the neck down to help with their atopic dermatitis symptoms. Water baths just use plain water. Even soap may not be necessary since it can irritate sensitive skin. Silverberg says a 10-minute soak in plain water will "wash away most the germs and crud from your skin,” and patients should moisturize their skin generously after each bath.
In addition to its effects on the skin, bleach can stain towels and other fabrics, and can sting or burn the eyes, as well as any open cuts on the skin. Silverberg says he’s also seen patients experience asthma flare-ups in reaction to bleach fumes.
"Patients with eczema have much higher rates of asthma than non-eczema patients," said Silverberg. "Everyone's home setting is going to be different, and many bathrooms don't have great ventilation, so a warm bath that causes the bleach to fume can be the perfect setup to potentially have an asthma flare-up."
Other adverse events (AE) reported in the pooled results included stinging and burning (6 of 56; 11%), itch (6 of 57; 0.5%), xerosis (4 of 38; 10.5%), erythema (2 of 29; 6.9%), urticaria (1 of 20; 5%), and oozing (1 of 20; 5%). There were no differences of AE between bleach and water baths.
In collecting results of previous studies, the authors noticed some flaws and inconsistencies. Many did not control for whether patients used soap or moisturizers in addition to their bath.
"This study provides a blueprint for improving future bleach bath studies," Silverberg said.