People with eczema often use moisturisers as eczema makes their skin very dry. But frequent use, plus impaired skin barrier function, increases their risk for allergic reactions to preservatives in those products, according to a new study.

In the study of 2 453 participants, researchers tested them for allergic reaction to preservatives found in skin care products. The results? Turns out those with eczema were more likely to have allergic reactions to quaternium-15, imidazolidinyl urea, DMDM hydantoin, and 2-bromo-2-nitropropane-1,3-diol, which are all preservatives that release formaldehyde, and able to penetrate the outer skin layers to activate immune cells. Those with eczema did not have a higher allergy rate for other preservatives, such as parabens, that do not release formaldehyde, say the researchers of the study. Though being allergic to formaldehyde releasers is not dangerous, it is very uncomfortable, much like poison ivy, says dermatologist and lead author of the study Dr Donald V Belsito. Can Bleach Renew Your Skin?

Micheal Dyrgaard Lunov from the National Allergy Research Centre in Copenhagen advises those with eczema to use ointments instead of lotions and creams. “Microorganisms require water to grow, and unlike lotions and creams, ointments don’t contain water, so they don’t need to contain preservatives. If people with eczema need to use lotions and creams, they should choose products preserved with parabens,” both Belsito and Lunov concur.