People with eczema are especially vulnerable to allergic
reactions to certain preservatives in lotions and creams, according to a new
With eczema, the skin doesn't function as a barrier the way
it normally would, said senior author Dr Donald V Belsito, a dermatologist at
Columbia University Medical Centre in New York City.
People with eczema often apply lots of moisturizers and
topical medications to combat dryness and itchiness, Belsito said."The
more exposure, the more likely you are to develop an allergic reaction to a
chemical," he told Reuters Health.
In his study published in the Journal of the American
Academy of Dermatology, patients with eczema were more likely to have allergic
reactions to several cosmetic preservatives, called "formaldehyde
releasers," than people without eczema.
Of 2 500 people tested for allergic reactions in the study,
342 had eczema. After a battery of individual allergy tests, the eczema group
was more likely to have a reaction to preservative chemicals quaternium-15,
imidazolidinyl urea, DMDM hydantoin and 2-bromo-2-nitropropane-1, 3-diol. Many
things might cause these chemicals to be harmful, Belsito said.
One possibility is that this group can penetrate the outer
layer of skin and bind to immune cells, activating them. All of the chemicals
in this group also release formaldehyde.
Eczema patients in the study did not seem to be predisposed
to allergies to parabens, formaldehyde or diazolidinyl urea, which are not
formaldehyde releasers. It is unclear what makes the "formaldehyde
releasers" problematic, the authors write.
It could be that those products are more commonly used so
people with eczema have more exposure to them, and more opportunity to develop
About 8% of all people have irritation or allergic reaction
to formaldehyde itself, according to a previous study.
These are not dangerous allergic reactions, just very
uncomfortable, like poison ivy, Belsito said.
Skin reactions usually go away if you stop using the product
and see your doctor, who may give you a steroid cream, said Michael Dyrgaard
Lundov, a senior researcher at the National Allergy Research Centre in
Copenhagen, Denmark. He was not involved in the new study.
Eczema – which is an excessive immune response similar to
those in asthma and allergic reactions – causes painful, red scaly patches on
the skin. It's becoming more common, Belsito said, and in some areas up to 30%
of kids have it.
Some people with mild eczema haven't been diagnosed they
just think they have sensitive skin, he said. Eczema patients "should be
advised to treat their skin with ointments, which are unlikely to contain
antimicrobial preservatives," he said.
Microorganisms need water to proliferate, Lundov said.
Products without water, like ointments, therefore don't need to include
antimicrobials. Eczema patients should also avoid products with fragrance,
which can cause irritation as well, he said.
If eczema patients must use creams or lotions containing
antimicrobials, they should choose products preserved with parabens, Belsito
and Lundov agreed.
Parabens are one of the most common cosmetic preservatives,
in use for more than 70 years, according to the US Food and Drug Administration.
Less than 1% of people had a reaction to parabens in a previous study.
Allergic reactions depend on how potent a chemical is, how
often you are exposed, how much of the chemical is in the product you use and
the unique tolerance level of your own skin, Lundov said. "Despite the
massive use of parabens in cosmetic products the parabens are rarely a cause of
allergic contact dermatitis," Lundov said. "This is because it is not
a very potent allergen."
"Quaternium-15 and the other formaldehyde releasers are
used in lower concentrations and fewer products, but is still a bigger problem
because the releaser itself and the released formaldehyde are more potent
allergens than the parabens," he said.