[acecharly (OP)]

Any thoughts

Cheers Ace

[Bored chemist]

Hydrofluoric acid is probably widely considered to be the worst.
Not only does it burn the skin, but it soaks through it causing damage further in.
It's noted for being very painful.

I can personally vouch for the fact that concentrated sulphuric acid burns feel a lot like burns from something hot. They blister in much the same way too.

[CliffordK]

Many acids (and bases) can touch the fingers and skin with only mild effects, especially if rinsed off in a reasonable amount of time. 

I suppose I don't get anything too exotic, but have touched H₂SO₄, HCl, NaOH, KOH, and etc.  I think they tend to make my fingers feel kind of slimy, with burning only if I hit cuticles, open wounds, or other less protected areas.

The "thick skin" on the palms of your hands, as well as your feet is quite protective for many things.

[acecharly (OP)]

I used to run an electroplating shop chrome/Gold finnishes and when we needed to strip chrome from damaged products we had to use potassium cyanide to strip back the chrome before we used nitric to strip the nickel (when plating brass it has to be nickel plate before it is chrome plated). The guy who used to do this was an absolute monster of a guy and whilst making up the potassium cyanide solution got a tiny amount in a cut (it comes in kind of polystyrene looking balls) i have never heard anybody scream like that in my life that was only one occassion, on a different one he forgot to rinse of the potassium cyanide in a water dip before transfering to the nitric...we all got out fairly fast !!!!