“Slime” contact dermatitis: Case report and review of relevant allergens

Homemade “slime” is currently a popular childhood hobby that can cause allergic and irritant contact dermatitis. We describe a case of hand dermatitis due to homemade “slime” with a positive patch test to methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) and MI. The most common potential allergens in “slime” collected from a review of “slime” recipes found on the Internet are reviewed.     

Prevalence and cause of methylisothiazolinone contact allergy

Background: Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) has been one of the most frequent sensitizers since the 1980s. In 2005, the use of MI alone was approved for the preservation of cosmetic and household products in the EU. Before that, MI was used in industrial products, and the first cases of isolated MI contact allergy were published. Objectives: To present the prevalence and causes of MI contact allergy. Materials and methods: Patch test results from 2536 dermatitis patients tested with MI at Gentofte University Hospital between May 2006 and February 2010 were analysed. A retrospective investigation of medical records from MI‐allergic patients was performed to reveal the causes of their MI contact allergy. Results: Of patch‐tested patients, 1.5% had MI contact allergy. It was associated with occupational dermatitis, hand eczema and age above 40 years. Exposure to MI in cosmetic products was found in 12 (32%) cases, and exposure to MI in occupational products was found in 11 (30%) cases; 5 of the 11 were painters. Conclusions: The prevalence of MI contact allergy is already at the same level as that of other sensitizing preservatives, which have been on the market for several years, but no rising trend was identified. MI contact allergy was associated with both occupational and consumer products.     

Contact dermatitis from methylisothiazolinone in a paint factory

Introduction of new potential contact-sensitizing chemicals have in the past led to epidemics of contact dermatitis. A new preservative containing only methylisothiazolinone (MI) and not methylchloroisothiazolinone (MCI) has recently been introduced in the European Union for use in products, such as paint, glue and cosmetics. The objective of this article is to describe a factory outbreak of contact allergy to MI and MCI preservatives. This factory outbreak describes allergic contact dermatitis towards MI in 4 patients of 14 persons working at a paint manufacturer. Patch test results from all patients showed positive reactions for MI and MCI/MI. The reactions were stronger for MI than MCI/MI indicating a primary sensitization to MI. The combination of MCI/MI remains widely used, and therefore various patterns of exposure and sensitization could be seen in the future. Our data show that MI holds a potential for eliciting and propably inducing contact allergy in humans. Whether this preservative is safe to use in cosmetics where billions of consumers are exposed needs a care full monitoring.