Several humanoids had spots as a prominent features of their species. Trills had their spotting on the sides of their bodies from their temples down to their heels, Taresians had theirs on various parts of the face, and Talaxians had theirs all over their bodies, with the exception of the fronts of their faces.
When Jadzia Dax and Deral briefly dated on Meridian, Deral found her spots attractive and asked how far down they went and she replied, "All the way." Later, she suggested to Deral that they count each other's spots as a sexual innuendo, the joke being that they would have to be naked to do that. (DS9: "Meridian")
When Harry Kim was a child, he became afflicted with Mendakan pox, which made him break out in spots. As an adult, he had a dream about that incident and woke up with similar spots. He wondered if he was getting Mendakan pox again, but The Doctor discovered that it was, in fact, not. As it turned out, he was in fact implanted with Taresian DNA, which caused the spots among other symptoms. (VOY: "Favorite Son")