I worked in the darkroom for many years without gloves, or tongs for that matter--only using them for the real nasty stuff, or for mixing up chemistry. for regular tray processing, I would just use my hands--but after some years of that, on a daily basis, I developed dermatitis from all the wet time and using neutral pH cleansers at the end of the cycles. I had to go to a dermatologist actually and I still have some problems with that, even though I judiciously use nitrile gloves, and tongs now as well. My hands are just ruined though, when it comes to sensitivity. I have to use steroid creams to control the flare ups, which isn't great, but my hands will crack & bleed and they never heal. lotions and over the counter stuff doesn't work--only avoidance does. didn't use to be that way, but that's what happened. the daily exposure is what did me--so that's why I use gloves--not so much for any paranoia over the chemistry, but just to protect my skin. I can't even wear my wedding band anymore, because moisture and any soap crud might get caught up under it, and causes problems.
so how do you know if you have a problem? it will become unbearable, your skin will have some really nasty, unsightly stuff going on, and it won't heal. when this first happened to me, it took me almost four months to get over it. my hands were a mess, and they just hurt all the time because they were cracked all over the knuckles and in between fingers and stuff. I would wake up in the middle of the night and feel like my hands were burning because they itched so bad, but you can't scratch them because that just makes it even worse. I slept with cotton gloves on with my hands slathered in vaseline. they were so sensitive, that I couldn't use any soaps or cleansers for sure, and I developed a problem with lanolin as well, which I never had. so the only moisturizer I can use on my hands now really is petroleum jelly, which is great at night, but not so great when you're trying to work with negs & prints, so during the day I have to do this juggling act of trying to minimize exposure with really dry skin now as well. so...that's how you'll know..or that's how I found out anyways. bummer--but better than metol poisoning or latex allergy for sure.