Pineapple, can you tell me the name of the internal parasite that caused this? i have never heard of internal parasites causing red blotches or streaks.
Also if the fish is a recent import it also may show red blotches due to improper water conditions, oftenly a series of water changes to improve water quality will clear it up, along with examining your filtration to make sure that no improvements need to be done for long term stability. And if the condition seems to get worse then you should QT the fish and use antibiotics.