Methylisothiazolinone, an emerging allergen in cosmetics?

Simultaneous determination of multiclass preservatives including isothiazolinones and benzophenone-type UV filters in household and personal care products by micellar electrokinetic chromatography

In this work, a simple and reliable micellar electrokinetic chromatography method for the separation and quantification of 14 preservatives, including isothiazolinones, and two benzophenone-type UV filters in household, cosmetic and personal care products was developed. The selected priority compounds are widely used as ingredients in many personal care products, and are included in the European Regulation concerning cosmetic products. The electrophoretic separation parameters were optimized by means of a modified chromatographic response function in combination with an experimental design, namely a central composite design. After optimization of experimental conditions, the BGE selected for the separation of the targets consisted of 60 mM SDS, 18 mM sodium tetraborate, pH 9.4 and 10% v/v methanol. The MEKC method was checked in terms of linearity, LODs and quantification, repeatability, intermediate precision, and accuracy, providing appropriate values (i.e. R(2) ≥ 0.992, repeatability RSD values ˂9%, and accuracy 90-115%). Applicability of the validated method was successfully assessed by quantifying preservatives and UV filters in commercial consumer products.

Patch testing in patients with perianal eczema

INTRODUCTION AND OBJECTIVES

Reports show that between 25% and 78% of patients with anogenital dermatitis have positive patch test results. Consequently, patch testing would appear to be warranted in patients presenting with eczema in the anogenital region. The objectives of the present study were to identify the most common allergens in patients with perianal eczema and to determine which allergen series are most useful for patch testing in patients with this condition.

MATERIAL AND METHODS

We performed a retrospective review of patch test results in patients with only perianal eczema between 2001 and 2012.

RESULTS

Of the 37 patients with perianal eczema, 16 had a positive reaction; methylchloroisothiazolinone/methylisothiazolinone was the main allergen involved. With the exception of 1 case of sensitization to gentamicin, all the positive results with present relevance were to allergens from the standard series of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) or to the patient's own products.

CONCLUSIONS

In our experience, methylchloroisothiazolinone/methylisothiazolinone is the main allergen involved in perianal eczema, and sensitization often results from using wet wipes. Patch testing in perianal eczema should be based on the GEIDAC standard series and the patient's own products.

Contact dermatitis in a child from methlychloroisothiazolinone and methylisothiazolinone in moist wipes

Contact allergic reactions to methlychloroisothiazolinone/methylisothiazolinone also widely known as Kathon CG have been reported extensively reported. It is one of the most commonly used preservatives in rinse-off products, cosmetics, and others. Herein, a case of a 50-year-old girl is presented with chronic dermatitis in the anogenital area. The patient was patch tested and had positive reaction to Kathon CG. The detailed history taking revealed that the allergen was present in the moist cleaning wipes used instead of dry toilet paper. The presented case serves as a basis for a appraisal of the use of this preservative in wet wipes. In addition, the duration of the patch test protocol in children has also been discussed.

Six children with allergic contact dermatitis to methylisothiazolinone in wet wipes (baby wipes)

Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) is a combination preservative used in personal care and household products and is a common cause of allergic contact dermatitis (ACD). Recently, MI alone, without MCI, has been increasingly used in consumer products in attempts to minimize allergic reactions. Wet wipes are extensively tested and traditionally believed to be innocuous. MI in wet wipes ("baby wipes") has not been previously reported to cause ACD in children in the United States. Only 1 previous report of ACD in a child in Belgium has been recently reported. We report 6 children with chronic, perianal/buttock, and facial eczematous dermatitis, refractory to multiple topical and oral antibiotics and corticosteroids. All tested positive to MCI/MI on patch testing. None wore diapers. All patients had been using wet wipes containing MI (without MCI) to affected areas. Discontinuation of wipes resulted in rapid and complete resolution. This is the first report of pediatric ACD to MI in wet wipes in the United States, and the largest series to date. ACD to MI in wet wipes is frequently misdiagnosed as eczema, impetigo, or psoriasis. Wet wipes are increasingly marketed in personal care products for all ages, and MI exposure and sensitization will likely increase. Dermatitis of the perianal, buttock, facial, and hand areas with a history of wet wipe use should raise suspicion of ACD to MI and prompt appropriate patch testing. Rapid resolution occurs after the allergen exposure is eliminated. All isothiozolinones should be avoided in personal care and household products for these patients.