I think it varies by the individual tolerance. If you don't know your own tolerance, sure it is best to side on caution. I remember the big warning about handling tobacco when rolling your own. If you don't wear gloves, wash your hands immediately because of nicotine absorption. I thought that was dumb. You mean if I bathe in tobacco and I never need to smoke again? How great would that be!
Well I am an excessive hand washer anyway and going 30 minutes without washing my hands is a long time. But even putting it off as long as I can, I don't think I ever absorbed more than a cigarette worth of nicotine when handling tobacco. People who have worked in the fields picking tobacco all day would know better than I. But those that have have told me if you have zero tolerance and picking tobacco all day without gloves you will be super sick. But people with a high tolerance, the nicotine is nothing much to worry about without gloves.
I've worked with 100mg PG nic without gloves before and I have got a few drops on my skin before. I never noticed anything nic absorption related, just slightly itchy skin if you don't wash it off right away. The itchy skin could be from the nic, or maybe the PG. YMMV. Would I get really sick if I got 1000mg on my skin? I dunno, maybe.