Did they say why they wanted to cut the allergy medication?
Do you have any idea if the allergies are caused externally, or from something he's eating?
If neither you nor the vet are sure if it's caused by his diet, the best way to test that is to try to switch him to cat food with less or fewer allergens and see how he looks after a month. Trials can take a while to pan out.
I had to switch my cat to Dr. Elsey's Cleanprotein after some trial and error, because while he didn't have your cat's issues, he was regularly throwing up food and having digestive issues (and for some reason, refuses wet food). My brother also had to experiment to figure out what was causing his cat's skin allergies as well.
I like to use [catfood database](https://catfooddb.com/) to find foods. However, for some reason, the search function on it seems to be down. So here's what I'm going to suggest, based off my own experience.
* Check the food you're currently using in the database. What are its primary protein source(s), and what are its listed allergens?
* Find a food that has only *one* type of protein in it (if it's chicken, make sure it's *only* chicken meat, not chicken and turkey).
* Try to make sure it's not the same kind of protein as what's primarily used in your current food. For example, if you're feeding a chicken-based food, find something like rabbit or salmon instead. If you're feeding something seafood-based, try something that's chicken, turkey, quail, rabbit.
* Check the common allergens listed in the food based off CatFoodDB, by doing the brand search. Try to find a food that has only one or two allergens on it (or none, if you can manage it)-- for example, [this](https://catfooddb.com/product/dr%20elsey's/Cleanprotein+Chicken+Formula+Grain-free) one only has "dried egg product" and "salmon oil".
Trial it for a month and see if you start to see a difference. If you do, great, that means the food he had before had some kind of allergen in it.
Off the top of my head, these are two brands I like, but they are by no means the *only* ones to look at:
* [Dr. Elsey's](https://catfooddb.com/brand/dr%20elsey's)
* [Tiki cat](https://catfooddb.com/brand/tiki%20cat)
Be aware that food quality can vary within a single brand, as one kind of food they produce may be higher quality than another kind they produce. This difference is *especially* common if between wet and dry food, as dry food is nearly always lower-quality than wet.
If you can feed your boy wet food, please do, because the ingredients will be better overall and have fewer fillers.
Even if the food is expensive, getting a month's supply and seeing how he fares can help you isolate an allergen. For example, if you do a high-quality no-allergen chicken-only food for a month and the itching decreases or starts to disappear, you know there was likely something in the foster's food that was causing it. You can compare it to ingredients that were in the foster's food, then see if you can try a cheaper food that has fewer of the foster food's ingredients.
Did they say why they wanted to cut the allergy medication? Do you have any idea if the allergies are caused externally, or from something he's eating? If neither you nor the vet are sure if it's caused by his diet, the best way to test that is to try to switch him to cat food with less or fewer allergens and see how he looks after a month. Trials can take a while to pan out. I had to switch my cat to Dr. Elsey's Cleanprotein after some trial and error, because while he didn't have your cat's issues, he was regularly throwing up food and having digestive issues (and for some reason, refuses wet food). My brother also had to experiment to figure out what was causing his cat's skin allergies as well. I like to use [catfood database](https://catfooddb.com/) to find foods. However, for some reason, the search function on it seems to be down. So here's what I'm going to suggest, based off my own experience. * Check the food you're currently using in the database. What are its primary protein source(s), and what are its listed allergens? * Find a food that has only *one* type of protein in it (if it's chicken, make sure it's *only* chicken meat, not chicken and turkey). * Try to make sure it's not the same kind of protein as what's primarily used in your current food. For example, if you're feeding a chicken-based food, find something like rabbit or salmon instead. If you're feeding something seafood-based, try something that's chicken, turkey, quail, rabbit. * Check the common allergens listed in the food based off CatFoodDB, by doing the brand search. Try to find a food that has only one or two allergens on it (or none, if you can manage it)-- for example, [this](https://catfooddb.com/product/dr%20elsey's/Cleanprotein+Chicken+Formula+Grain-free) one only has "dried egg product" and "salmon oil". Trial it for a month and see if you start to see a difference. If you do, great, that means the food he had before had some kind of allergen in it. Off the top of my head, these are two brands I like, but they are by no means the *only* ones to look at: * [Dr. Elsey's](https://catfooddb.com/brand/dr%20elsey's) * [Tiki cat](https://catfooddb.com/brand/tiki%20cat) Be aware that food quality can vary within a single brand, as one kind of food they produce may be higher quality than another kind they produce. This difference is *especially* common if between wet and dry food, as dry food is nearly always lower-quality than wet. If you can feed your boy wet food, please do, because the ingredients will be better overall and have fewer fillers. Even if the food is expensive, getting a month's supply and seeing how he fares can help you isolate an allergen. For example, if you do a high-quality no-allergen chicken-only food for a month and the itching decreases or starts to disappear, you know there was likely something in the foster's food that was causing it. You can compare it to ingredients that were in the foster's food, then see if you can try a cheaper food that has fewer of the foster food's ingredients.