Itrafungol is a systemic fungal treatment; it should work within a few days. Canesten 2% cream has worked for fungal piggies of mine in conjuction with either systemic fungal or fungal baths/dips (the best of which for ringworm turned out to be imaverol, which you can order over the internet).
The thing with ringworm is that it has to get worse before it gets better. The affected area is bigger than you can see. All the affected hair needs to come out, as the fungus also sits at the roots of hair. If it stays in, it can start up again.
I have found that imaverol dips help well with ringworm in the affected areas and makes it much easier to remove the affect hair.
Please be extra careful when handling your piggies and in disinfecting their cage and everything in it ideally now and at the end of the treatment again! Make extra sure that you wash/disinfect your hands and also take care with any fabrics that come into contact. I once managed to carry the infection back through a pullover I used during the treatment. If you develop any very burning-itchy spots that are fainly pink rimmed, please see your gp or a pharmacist asap.
Here are some pics of piggies of mine to show you how ringworm evolves. My piggies have treated straight away and were responding to treatment promptly, yet the fungal had to run its due course:
Start: often with a scab in the face that looks like a scabbed over scratch; here the area between the scab and eye is starting to be affected as well.
Furthest extent, after imaverol dip; you can see the area where affected hair has newly come off.
Furthest extent, healing off:
Healing off: hair is growing back in the parts that were attacked first