he doesn't have lateral line disease. I wouldn't feed him kanaplex or anything else unless an actual infection appeared. -it's likely damage from fighting, possibly running into rocks while chasing chromis.. bacterial and fungal infections look like growths coming out of the wounds, cottony or bumpy.
if your clowns are bullying chromis your tank is too small. mated pairs of clownfish always get very territorial. they'll usually stake out about 10gallons-20gallons of tank space as their own. (maroon clowns and clarkii will go to about 40 gallons of space). They'll bite you too if you put your hand in their space.
if he does somehow have lateral line disease... (I highly doubt) feed a variety of frozen foods.. live black worms maybe (you can order them online).. ignore the people who say garlic(a lot of ppl say this for HLLE).. it can help if a fish isn't eating, it's an appetite stimulant, but has no nutritional value to fish.