Time trends of contact allergy to the European baseline series in Lithuania.

Background: Monitoring trends of positive patch test reactions is useful for epidemiological surveillance and contact allergy prevention, and has not previously been reported in Lithuania.

Objective: To examine and compare changes in the prevalence of contact allergy to European baseline series allergens in adults with suspected contact dermatitis during a 9-year period.

Methods: In this retrospective study, patch test results of 297 consecutive patients, tested with the European baseline series in 2014-2015, were analysed and compared with the data published earlier in Lithuania.

Results: The most common allergens were nickel sulfate (30.6%), methylisothiazolinone (MI) (13.5%), methylchloroisothiazolinone (MCI)/MI (7.4%), potassium dichromate (6.1%), cobalt chloride (6.1%), Myroxylon pereirae resin (5.4%), p-phenylenediamine (5.4%), fragrance mix I (4.7%), formaldehyde (4.4%), and methyldibromo glutaronitrile (3.7%). Increases in the prevalence of sensitization to MCI/MI (2.3% in 2006-2008 and 7.4% in 2014-2015; p < 0.0001) and nickel sulfate (16.4% in 2006-2008 and 30.6% in 2014-2015; p < 0.0001) and decreases in the prevalence of sensitization to paraben mix (3.2% in 2006-2008 and 0.3% in 2014-2015; p = 0.006) were observed. Prevalences for the other allergens remained stable or showed a decreasing trend (Myroxylon pereirae resin; p = 0.06).

Conclusions: This study provides current information on the prevalence of contact allergy in Lithuania. Changing trends in sensitivity to some allergens probably reflect changes in exposure.