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Dermatologists raise the alarm on a contact allergy epidemic

At a special session of the British Society of Cutaneous Allergy to be held at the British Association of Dermatologists’ Annual Conference in Liverpool next week (July 8th to 11th), leading dermatologists will present research highlighting their fears of a new epidemic of contact allergy (causing eczema) to two chemical preservatives.

The ingredients in question are Methylisothiazolinone (MI) Methylchloroisothiazolinone/Methylisothiazolinone (MCI/MI). It is their presence in personal care products that are causing most concern, for example moist tissue wipes, cleansers, shower gels, deodorants, shaving foam. They can also be found in household products such as washing up liquid.

The preservatives are often used together, and past concerns about MCI/MI in Europe led to reductions in the concentrations allowed in cosmetic products.

Despite this a team at the Leeds Centre for Dermatology show in their research (1) that there was a sharp rise (up to 6.2 per cent sensitivity) in contact allergy to MCI/MI and MI over the past three years.

This was also reported by a team of researchers at St John’s Institute for Dermatology at St Thomas’ Hospital in London (2) who had seen a rapid rise in contact allergy to MI in the last two years going from one case in 2010 to 33 cases in 2012 – they also note that reports of high levels of MI allergy are emerging from several European countries. Across the UK other dermatology centres are also noticing rapid rises in numbers of acute allergic contact dermatitis related to MI exposure.

It is suspected that the recent use of MI as a single agent preservative in quantities up to 100 ppm in personal care products may be a major contributor to this outbreak of MI allergy.

David Orton, President of the British Society of Cutaneous Allergy said:

“Across the large patch test centres 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.

“The last time a preservative had this type of effect it was banned by the EU. Although the relevant bodies in Europe have set up a review this all takes time – in the meantime the number of people coming to see us with this allergy is only likely to rise.

“We would welcome the opportunity to meet and discuss this issue with representatives of the UK cosmetics industry so as to take immediate steps to protect UK consumers”.

Dr John McFadden, Consultant Dermatologist at St John’s Institute of Dermatology said:
“The time for action is now. We are in the midst of an outbreak of allergy to a preservative (MI) which we have not seen before in terms of scale in our lifetime. Many of our patients have suffered acute dermatitis with redness and swelling of the face. I would ask the cosmetics industry not to wait for legislation but to get on and address the problem of MI allergy before the situation gets worse. If they are already taking action we would urge them to be open and transparent about what steps they are taking”


Notes to editors:

If using this study, please ensure you mention that the study was released at the British Association of Dermatologists’ Annual Conference.
The conference will be held at ACC Liverpool from July 9th to 11th 2013, and is attended by approximately 1,300 UK and worldwide dermatologists and dermatology nurses.

For more information please contact: Nina Goad, Head of Communications, 0207 391 6094 (or mobile 07825567717 during conference week only) or Deborah Mason, Communications Manager, Phone: 0207 391 6355, Email:, Website:

1) Methylchoroisothiazolinone and methylisotiazolinone contact allergy: a new epidemic, R. Urwin and S.M Wilkinson, The Leeds Centre for Dermatology, Leeds. UK
2) Outbreak of contact allergy to cosmetic preservative: history repeats itself (again), J.Mann, I.White, J.White, P.Bannerjee and J. McFadden, St John’s Institute of Dermatology, St Thomas’ Hospital, London, UK

1) Abstract CD01 Methylchloroisothiazolinone and methylisothiazolinone contact allergy: a new epidemic
R. Urwin and S.M. Wilkinson
The Leeds Centre for Dermatology, Leeds, U.K.

Methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are commonly used preservatives (biocides) in industrial and household products including cosmetics. Despite a reduction of maximum permissible concentrations of MCI/MI in leave-on and rinse-off products (7_5 p.p.m. and 15 p.p.m., respectively) in 1992 (Cosmetic Ingredient Review Expert Panel of The Cosmetics Toiletry and Fragrance Association. Final report on the Safety Assessment of methylchloroisothiazolinone and methylisothiazolinone. J Am Coll Toxicol 1992; 11: 75–128) due to a European epidemic of MCI/MI contact dermatitis, the incidence of contact allergy remains high at approximately 2% (Lundov MD, Krongaard T, Menn_e TL, Johansen JD. Methylisothiazolinone contact allergy: a review. Br J Dermatol 2011; 165: 1178–82). MI alone was introduced in industrial products in the early 2000s. Case reports of occupational contact allergy from exposure in paints followed. In 2005, MI alone was permitted in cosmetic products (maximum concentration 100 p.p.m.). Concentrations of MI in patch testing have varied, but an approximate prevalence of 1_5% has been estimated, with 0_2% aq. (2000 p.p.m.) considered the optimal test concentration. Over the past 4 years there has been suggestion of an increasing trend for sensitization. A retrospective cohort study was conducted from a database of subjects undergoing standard patch testing to the British Society of Cutaneous
Allergy (BSCA) baseline series from 2008 to June 2012. MCI/MI was tested at concentrations of 0_01% aq. (100
p.p.m.) up to 2008 and at 0_02% aq. from 2008. MI was tested at 0_02% aq. from 2009 onwards and additionally at 0_2% aq. from 2011. An increased prevalence of MCI/MI contact allergy over time was demonstrated in 4_9% of those patch tested, with a measurable increase of MI sensitivity over 3 years to 4_6%. Between January 2011 and June 2012, 6_2% of patch-tested patients had allergy to MCI/MI and/or MI at any concentration. This trend is most likely due to increased use in products, and reassessment of current usage and regulation of MCI/MI should be considered. Increased use of MCI/MI and MI could also be explained by the need for an alternative preservative to methyldibromoglutaronitrile following its prohibition from all cosmetic products in Europe since 2008. Testing MI 0_2% aq. compared with 0_02% aq. resulted in a near doubling of the detection of MI sensitivity, suggesting that future testing should involve 0_2% aq. concentrations.

2) Abstract CD02 Outbreak of contact allergy to cosmetic preservative: history repeats itself (again)
J. Mann, I. White, J. White, P. Banerjee and J. McFadden
St John’s Institute of Dermatology, St Thomas’ Hospital, London, U.K.

Methylisothiazolinone has been used in combination of 1 : 3 with methylchloroisothiazolinone as a preservative in toiletries and household products since the 1980s and is currently regulated in this combination to a level of 3_75 p.p.m. It has also been used in wall paints and in industry. This combination has represented a common cause of preservative allergy since then but usually at a reported prevalence rate of < 1_5% from patch test clinics. On the basis of in vivo reports suggesting that methylisothiazolinone is only a moderate sensitizer, it has been allowed in toiletries and household products up to a reported safe limit of 100 p.p.m. Since July 2010, methylisothiazolinone has been included in our cosmetic series. Over the last 2 years there has been a rapid rise in contact allergy to methylisothiazolinone. There were 33 cases (5_7%) in 2012, up from 18 (3_5%) in 2011 and 1 (0_5%) in 2010 (2010 vs. 2011, P < 0_05; 2010 vs. 2012, P = 0_0015). The majority of cases were women over 40 years of age: 17 (8_8%) in 2012 and 15 (7_4%) in 2011, there having been no cases in 2010 in this group. In most cases contact allergy was relevant to the presenting dermatitis (definite relevance 69%; possible relevance 31%) with onset/exacerbation of rash within the previous 2 years (71%). Sources of exposure were diverse, including moist
tissue wipes, cleansers, toners, shower gel, shave foam, mascara, hair products and washing-up liquid. Reports of high levels of methylisothiazolinone allergy are emerging from several European countries. Outbreaks of preservative allergy have been regularly observed in Europe every 5–10 years, perhaps from too high a concentration of preservative being permitted after toxicological data, which, in retrospect, did not reveal the potential hazard. That human and animal data were available for the analysis of the sensitizing potential of
methylisothiazolinone and the failure to identify the risk of sensitization when used in cosmetics at 100 p.p.m. is of considerable concern. In future, animal and human data will not be available for risk assessment when new preservatives are brought into use in Europe. This outbreak also highlights the lack of a formal reporting system at present, although cosmetovigilance is being introduced.

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