IL4 and allergic contact dermatitis: Pro-inflammatory cytokines such as TNFα, IL-4, IL-6, IFNγ and increasingly, IL-17 (Cosmi et al, 2014, Incorvaia et al, 2008, McFadden et al, 2013, Taniguchi et al, 2013, Watanabe et al, 2002) are likely to play an important role in allergic contact dermatitis and other inflammatory skin conditions.