Another source of allergic contact dermatitis to isothiazolinones in children—urgent call for regulation

Methylchloroisothiazolinone/methylisothiazolinone and methylisothiazolinone contact allergy: A 24-year, single-center, retrospective cohort study from Turkey

BACKGROUND

Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and MI allergy caused a global epidemic during the period 2010 to 2015, reaching its peak in 2013/14.

OBJECTIVE

To investigate the characteristics of MCI/MI and MI allergy in Turkey over 24 years.

METHODS

A total of 2310 patients patch tested between 1996 and 2019 with MCI/MI 0.01% aq. or MCI/MI 0.02% aq., with or without MI 0.2% aq., were analyzed.

RESULTS

The overall prevalence of contact sensitization was 3.3% (n = 77) with a peak level of 16.4% in 2015. The prevalence gradually decreased thereafter, but was still high (6.5%) in 2019. Seventy-three patients had clinically relevant sensitizations. MI could detect clinically relevant sensitizations in all seven patients with a negative patch test reaction to MCI/MI 0.02%. Non-occupational allergic contact dermatitis (ACD) was most frequently seen, mainly in women, with hand/face eczema from rinse-off or leave-on cosmetics, such as wet wipes. Occupational ACD was mainly seen among men with airborne eczema from wall paints in house painters, or with hand eczema from hair gel/wax in men's barbers.

CONCLUSIONS

The prevalence of MCI/MI and MI sensitization in Turkey following the peak in 2015 is still high. This is probably due to the currently allowed level of 100 ppm for MI in rinse-off cosmetics. This needs to be urgently reduced.

Allergic contact dermatitis in children and proposal for an Australian Paediatric Baseline Series

BACKGROUND

Allergic contact dermatitis (ACD) is an increasingly common diagnosis in children. The objectives of this study were to review our experience with ACD in children in tertiary settings, to ascertain the spectrum of allergens in this population and to subsequently propose the first Australian Paediatric Baseline Series for patch testing.

METHODS

We conducted a retrospective analysis of patch test data from 1993 to 2017 from two tertiary referral patch-testing centres in Melbourne, Victoria.

RESULTS

A total of 511 children were patch tested during the study period. Of these, 58.3% (298/511) of children tested had a positive patch test, and 65.1% (194/298, or 38.0% of the total) had a relevant positive patch test. The most common relevant patch test reactions were fragrance mix, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and methylisothiazolinone (MI), Myroxylon pereirae, nickel sulphate, and colophonium.

CONCLUSION

Allergic contact dermatitis is not uncommon in children, and patch testing should be considered in children with suspected ACD or with recalcitrant atopic dermatitis. Based on our experience over 25 years, we propose the first Australian Paediatric Baseline Series.