Allergic contact dermatitis (ACD) is now recognized as a common relevant diagnosis in children. We reviewed the results of patch tests in children under 16 years of age over the 3-year period January 2009 to December 2011, comparing the results with those in a similar 3-year retrospective study performed in our unit for the period August 1999 to September 2002. In total, there were 137 children (70 girls and 67 boys) aged 3-15 years enrolled. Of these, 28 girls (40%) and 22 boys (32.8%) had a positive reaction to at least one allergen, with nickel sulfate and potassium dichromate being the most common allergens, each having an incidence of 7.2%, in contrast to the 20% incidence of nickel allergy in 1999-2002. The rate of fragrance allergy was unchanged at 5.8%, and rubber allergy incidence was greatly reduced. These results show that allergens may be changing in children, and that patch testing is still a useful test to consider.