I´d second the doc, just to be sure. But I also had something that looked like that. First I thought it´s a pimpl, but one of them turned black rather than white. I also got a bit concerned. I had 3 in almost the same location some time ago. It took a few weeks until these "volcanos" looked better. 1 is gone completely, the other one almost and the 3rd most prominent one left a white spot. Pretty sure these were not spiders, as there were none where I lived. I had thought that these could be diet related, oxalates was one of my suspects, as at the time I was eating quite some chocolate and I know that oxalates can cause major skin issues.