I've been trying to find any definitive information anywhere about UV effects on allergic contact dermatitis (sun/tanning bed effects on the rash). There is no posted literature that I could find. There are always discussions about photosensitivity in sensitive individuals as well as discussions about photodermatitis (I think I just misused the term there but its about rashes appearing due to exposure to the sun / UV rays on sensitive skin). So probably a non-issue as you mention in your post. If I ever come with something definitive I'll definitely post here.