another set of questions- allergies/acne

[October]

Murphy has had a couple bouts of chin acne in spite of eating from dinner plates the whole time we've had him. After doing some reading about it and informally asking a vet tech who cat-sat for him, I figured out you can just ignore it and it'll go away on its own. I guess it's something that's just going to happen every now and then, but fortunately it's "no biggie," as the vet tech said.

[Tina]

I think it's good that you're getting him off Friskies. My cat has similar issues. We have not been able to narrow down what causes it. I volunteer at a shelter and get good regular advice from the vets there. As for the nose and eyes, like the other poster said add Lysine. As for the chin it would be good to wash her chin twice daily. I've been using a fragrant free Aveeno with oatmeal wash. Vet also said you can dab the chin with a bit of rubbing alcohol to dry it out. Ensuring your cat is getting enough proper fatty acids help too. The Friskies food could very well be the culprit.

[mrsKoach]

So the vet said to do the limited ingredient diet to eliminate as many culprits as possible and then add them in one at a time. He's been 10 days on the Evo and the difference is amazing. The downside is that he's dropped a little weight. Just under 9lbs now and the vet still wants to see him up to between 10-11lbs.
Since the Duck is his favorite Evo, should I start with the Natural Balance limited Duck for a couple weeks (she said 2-eight) and add in from there? Maybe the Evo duck back in and then try a turkey, beef, chicken, etc?
I'm 99% sure grains (corn, etc), fish (not sure on the oil), and chicken are allergies. Beef is iffy. He won't touch the venison Evo.
Are there any other grain-free chicken-free foods?
How do I get him to gain more weight? He eats a whole can of Evo (5.5oz) split 3x a day. Should I get some good dry and add that as a snack at the end of the day? 1/8C or so? Add in another 1/3 can until the dry gets in since I have to order it? I don't ever expect him to be a chunky kitty. I just know he's too thin and the vet knows he's too thin.
And thanks for the advice on his chin! I'll go back to washing and putting some rubbing alcohol on it.

Thanks again!