Help – sharpnose puffer in trouble

[Seafan]

I’ve had this 3” blue-spot sharpnose puffer in my 10g quarantine tank for 2 weeks. 2 days after I got him I saw him scratching on the rocks many times. So I fed him garlic soaked shrimp and scallops, and the scratching reduced to only a few times a day. He has been very active and a greedy eater, but yesterday he ate much less than usual, and spent most time hiding under a cave, sitting on the tank bottom. After some close inspection, I found that there was a small area on his side, about 0.5” by 0.25”, where his scales looked “lifted” or “erected” for a lack of better description. I suspect it’s from his scratching on the rocks. He looked lethargic. I was afraid of infection in the described area so I treated with some Melafix. Is there anything else I could/should do at this point?
Thanks!

[Ninong]

^

[organicreefer]

i may be alot late on this reply but...
is the fish respiring rapidly?are the eyes cloudy ?any whitish blochtes?popeye?
is the abdomen distended ?does he have loss of equilibrium?dark nodules under the skin?
sounds like either piscine tb(first set of symptoms)along with raised scales ,listlessness and not feeding well
or an internal fungus infection(second set of symptoms)along with raised scales ,listlessness and not feeding well
hth