Products designed to clear away blemishes may instead have the opposite effect, new research finds, as dermatologists have connected two key preservatives in many cosmetic and sanitary products to cases of acute allergic contact dermatitis.

The preservatives known as MI and MCI have been found in Nivea skin lotion, some L'Oréal creams, and Wet Ones cleaning wipes, not to mention other varieties of mascara and shower gels. The majority of the allergic reactions occurred in women over the age of 40, with exposure to the preservatives resulting in facial swelling, hives, itching, and redness.

While Wet Ones and L'Oréal insist their products are safe, Dr. John McFadden, consultant dermatologist at St Thomas' Hospital, London, wants cosmetic companies to act before legislation demands them to.

"We are in the midst of an outbreak of allergy which we have not seen before in terms of scale in our lifetime," he said. "I would ask the cosmetics industry not to wait for legislation but to get on and address the problem before the situation gets worse."

McFadden's team at St. John Institute for Dermatology has seen an increase from one case in 2010 to 33 cases in 2012.

"Sources of exposure were diverse, including moist tissue wipes, cleaners, toners, shower gel, shave foam, mascara, hair products and washing up liquid," his report found.

McFadden's report has parallels to other studies, which seem to echo his team's findings.

The American Contact Dermatitis Society named MI "contact allergen of the year" for 2013, in order to generate awareness of the preservative's potentially harmful effects.

"Across the large patch test centers in the UK, data suggest that rates of allergy to these two preservatives are now nearing 10 per cent - and in some cases higher - this is clearly far too high and is an unacceptable situation," said David Orton, president of the British Society of Cutaneous Allergy. "The last time a preservative had this type of effect it was banned by the EU."

The preservatives MI and MCI have been used since the 1980s in more industrial products, such as wall paint, and have only recently started to appear in cosmetic products. The preservatives full names are methylisothiazolinone (MI) and methylchloroisothiazolinone (MCI).

A sharp rise in allergies linked to the preservatives was also found by a team at the Leeds Center for Dermatology, at 6.2 percent over the last three years. The team cited the .01 percent legal limit for MI as being too high.

However, Dr. Emma Meredith, head of scientific and technical services at the Cosmetic, Toiletry and Perfumery Association, said the dangers are overstated and that patch testing is an important way of seeing if an individual reacts to allergens.

"If there is a positive reaction to a patch test it does not necessarily mean a reaction will occur on exposure to a cosmetic product, and the small amounts legally allowed," she said.

The current legal limits for each preservative in a commercial product are .01 percent for MI and .0015 percent for MCI.

Products that contain the ingredients include Nivea body lotion and facial cleaning wipes, Wet Ones, Piz Buin 1 Day Long Lotion, and L'Oréal Revitalift Laser Renew moisturizer.