Verruca vulgaris, the common wart, is caused by a papilloma virus, of which there are many, though most warts come from types 1, 2, or 3. (There are other kinds of warts, and I won't offer them up here, too much information.)
Common warts, unlike the genital ones, are generally harmless, more a cosmetic nuisance, though sometimes they pop up in places that interfere with some activity, especially on the hands.
As a teenager, I was afflicted with the suckers, and spent several unpleasant sessions at assorted doctors's offices having them cut or burned off my hands or feet; and later, frozen with dabs of liquid nitrogen. (You can now buy stuff over the counter that will ice the little beasts, small and expensive aerosol cans of what is essentially ether, that produce pretty low temperature, albeit not as cold as liquid N. Freezing is the current preferred method by the medical establishment. Dry ice will do, as well.
The wart-off liquids you get that are room temp are acids, as are the plasters, they don't work as well, and they are more apt to scar.)
Freezing the wart and bit of surrounding tissue is a lot like frostbite. You get a blister, the affected tissue essentially dies, and is sloughed off, and usually the wart goes with it.
This does not get rid of the virus in your system. Like herpes, once you have it, you tend to have it forever, and it might be six months or sixteen years, but another wart can pop up.
Folk medicine has a lot of treatment methods. I've always like the swinging-a-dead-cat-over- your-head-at-midnight-in-the-graveyard version from Tom Sawyer, though I suspect its efficacy is slim.
Rubbing the little lumps with the inside of a banana skin supposedly works. So too, garlic, dandelion juice, vitamin C, raw potato, even hypnosis.
And duct tape. (Actually, any kind of tape. I think the popular theory is that keeping the wart covered somehow "suffocates" it. You have to change the tape frequently because it tends to fall off. I suspect that dabbing the wart with super-glue or nail polish might achieve the same effect, though the mechanism here isn't nailed down -- I don't think air has anything to do with it. The most reasonable theory is that keeping it covered somehow stimulates the immune system. Since warts sometimes disappear spontaneously without treatment, this could be the answer.
All of which is to say that I have, after some years of being wart-free, developed a small one on my left thumb, near the distal joint, palmar side. Last time I had one, I used one of the OTC freezers and after the blister dried up, the wart was gone. I still have some of that compound somewhere, but just to see, I decided to try the tape route first. I'm using bits of stretchy, waterproof band-aids, and after a few days, somewhat to my amazement, the thing is already smaller. I'm going to give it two weeks -- or it goes away -- whichever comes first.
If it works, great. While it takes longer, it's cheap and painless. If it doesn't work, I can zap it with the cold stuff, but that does sting a bit, and makes fretting the guitar a little trickier with a blister right there.
Stay tuned ...