You can't really know for sure, but perhaps some managed to, I would doubt it though. If you see more white spots cropping up I would just add some ich-attack to the tank. You will be able to use this in conjunction with epsom salt, high temperature, and maracyn/maracyn II (if you end up using it).
Poor guy. Have you added the Epsom salt? A good dosage for popeye is 1 teaspoon per gallon of tank water.
Once he's in the Epsom salt, it may take a day or two for the swelling to go down.
If the Epsom salt isn't effective, then go to the Maracyn/Maracyn II combination. Or you could try a broad spectrum medication like a sulfa drug. (Don't use this if you're allergic to sulfa drugs though.) API Triple Sulfa and Mardel Maracyn Plus (must be 'plus') are both good sulfa drugs, if you decide he needs medication.
I wouldn't worry about the temp dropping to 84F during the water change. Most likely, it won't make a difference. Worst case, some of the parasite managed to reproduce, which just means you'd need to keep the temp at 86F for a little longer.
Alright, I decided to be a little safe and not use the Ich Attack just yet.
I did a roughly 75% water change, and the new water has water conditioner and Epsom Salt. He's still really hungry, and I'm so proud of him for being brave and keeping up his appetite. It's too bright here to check on the Ich, but his Popeye is still pretty bad. I have a second batch of water prepared for an afternoon water change, but my main question is how much Epsom Salt do I put in it? I read it's not good to add more salt during water changes because you're not taking an even amount out and replacing it. That being said, he doesn't have an even amount of in there either since since there was still about 25% old water.
It can be quite difficult to treat multiple issues at once. In my opinion the best thing to do is treat the most pressing need first, then move on to the second. I don't like to mix all different kinds of treatments, though I'm sure there are some that you can, just like with meds that we take.
I never use salt for anything. I'm sure someone who does can provide better help.
How much you salt you need to add is dependent on how much water you change. If you have a 10 gallon and have 10 parts of salt (for an example) and change 50% of the water (5 gallons), then you would add 5 parts of salt with that water. However, when water evaporates salts are left behind so if the water level has dropped, then it becomes a little trickier. Say you lost 2 gallons and now have 8 gallons of water with 10 parts of salt....if you removed 4 gallons of water, you would also be removing 5 parts of salt, so you would refill with 6 gallons of water and 5 parts of salt. Say you lost 4 gallons to evaporation....then in doing a 50% water change, you would be removing 3 gallons of water - but still 5 parts of salt. So when refilling, you would add 7 gallons of water and....... 5 parts of salt. Follow?