After looking at the pics I don't think it is hith but maybe, it could be dermocystidium or a bacterial lesion. I'm hoping someone will speak up on hith as I don't have much experience with it. All of these benefit from improve tank hygiene and a more varied diet as vitamin deficiencies can lower resistances, esp. in the case of dermocyystidium.
All can lead to fungus infections so heat and salt as for ich for 14 days probably won't hurt and watch closely for a fuzzy appearence on the lesions, if you see that start use a fungicide after reading the instructions for interactions with salt. Remove any charcoal from your filter system now. it can aggravate hith and negate any mads you use.
There is no cure for dermacystidium but it goes away on it's own. With out a rigid program of tank cleaning an d standard water changes it often comes back and can lead to the bacterial lesions I am about to talk about.
Several years ago I had angel fish come down with open whitish sores, I found an old treatment for them and it worked. Several modern sites still describe it and it won't do any further hurt to fungal infected fish or those with dermocystidium,
the pic is a fish with bad bacterial ulcers, it lived. the pic is from a british site called fish doc.
Prepare a dip tank of clean dechlorinated water, 2 liters will do, bring it to the same temp. as your tank and add an air stone add 20mg.of pottassium permanganate (for 2 liters) purchased from your lfs or pharmacy. Place the affected fish in it for 15-20 minutes then put them back in your tank, repeat this once a week for three weeks even if it clears up sooner.
In the mean time add an antibiotic such as oxytetracycline to the fishes food at what ever ratio (usually 1%) called for on the bottle and feed with that for 10 days.
the ulcers should be well on there way to healing by the time the treatment is over.
On the up side it does not look like tuberculosis.
