Forskning ved Københavns Universitet - Københavns Universitet


Patch testing with methylchloroisothiazolinone/methylisothiazolinone 200 ppm aq. detects significantly more contact allergy than 100 ppm. A multicentre study within the European Environmental and Contact Dermatitis Research Group

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • Magnus Bruze
  • Marléne Isaksson
  • Birgitta Gruvberger
  • Klaus E Andersen
  • Margarida Gonçalo
  • An Goossens
  • Johansen, Jeanne Duus
  • Howard I Maibach
  • Thomas Rustemeyer
  • Christophe-J Le Coz
  • Ian R White

BACKGROUND: Methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are the active ingredients in commonly used preservative systems (e.g. Kathon CG(®)). MCI/MI is present in the European baseline patch test series at 100 ppm aq. Since 1986, 200 ppm (dose 0.006 mg/cm(2)) has been used in Sweden without causing skin irritation. Centres in Spain, the United Kingdom and Ireland have also used 200 ppm in their baseline series.

OBJECTIVES: To find the optimal patch test concentration for MCI/MI.

MATERIALS AND METHODS: MCI/MI 100 ppm aq. and MCI/MI 200 ppm aq. were simultaneously patch tested in 3300 consecutively tested dermatitis patients at eight European patch test clinics and one US patch test clinic. With the Finn Chambers(®) technique (diameter 8 mm), 15 µl was micropipetted on to the filter paper in the chamber. The corresponding volume for Van der Bend(®) chambers was 20 µl, and that for IQ Chambers(®) was 25 µl.

RESULTS: Contact allergy to MCI/MI at 100 and 200 ppm was found in 1.2% and 2.1% of patients, respectively (p < 0.001).

CONCLUSIONS: MCI/MI 200 ppm aq. (dose 0.006 mg/cm(2) ) diagnoses significantly more contact allergy than the presently used concentration of 100 ppm (dose 0.003 mg/cm(2)), without resulting in more adverse reactions. MCI/MI at 200 ppm should therefore be considered for inclusion in the European baseline test series.

TidsskriftContact Dermatitis
Udgave nummer1
Sider (fra-til)31-34
Antal sider4
StatusUdgivet - jul. 2014

ID: 138612728