Such involvement of dermal lymphatics gives the grossly thickened, erythematous, and rough skin surface with the appearance of an orange peel ("peau dorange" for you francophiles).
There's very little dermal absorption, skin allergy reactions, irritants, reactions, so the less regulation there in Europe has given them more options.
Despite its smooth external appearance, at the micro level, it has a coarse texture thanks to thousands of tiny teeth-like scales called dermal denticles.
And this arrangement is really interesting, because it combines both the normal, internal skeleton of the ankylosaur with the protective dermal skeleton to make a single structure.