Is it just irritated? Or could it be a skin infection (bacteria, yeast) from the bandage getting wet?

If it’s just irritated, you could put some ointment on the area to help it heal. Things like plain diaper rash ointment (no zinc), silvadene cream, Bag Balm, etc. are all suitable.

Fucidin an antibiotic ointment. So the fur and skin were torn when the bandages were removed? Ouch!

You can clean the area to keep it from getting infected. Wound cleaner like Vetericyn or chlorhexidine could be used. Aside from that, there isn’t much else that can be done except for an ointment of some kind. I would think one for diaper rash might have a little more staying power.

It doesnt have to get infected, so normally I’d just recommend keeping it clean (fore example rinse it with chlorhexidine solution like LBJ suggests, or plain saline (like human eye wash).

If ointment of any kind makes him lick the area more, I’d skip using ointment. Animals do like to lick their wounds, but they can do more damage to the skin if they lick too much. If the skin is wet all the time, it can become a perfect  breeding ground for fungi and bacteria.

If he busies himself to much with the sore spot, you may need to use a cone or e-collar to prevent him from reaching it. Hopefully it won’t come to that.

If the “dirt” is the litter box, then probably not. Just keep his litter box clean and clean the wounded area.

Bam has a point about using ointment. If it makes him not leave the area alone, then I could see it making the irritation worse. I assume the Fucidin is “wetter”, like triple antibiotic ointments are. So switching to something that actually rubs into the skin a bit may work better (e.g. diaper rash ointment)… or, as Bam suggested, you could go without the ointment altogether if he won’t leave the area alone because of it. I think it really depends on the circumstances because sometimes bunnies will mess with the area more when ointment isn’t used as the site becomes itchy.