Pemphigus vs Allergies

Location: Canada

Vet Accessible: we just visited today and have a follow up next week

TLDR: Has anyone had a cat that had either Pemphigus or (food) allergies? Causing gunk between the toes and skin issues. We’re hoping it’s allergies but can’t afford a biopsy.

Age: 2 years

Sex: Male and neutered!

Financial situation: we can’t really afford too much but we’re trying

We had our cat examined today because he’s had some hair loss and a scabby spot on his shoulder. He’s also had this crud building up around his toes. After looking at him the vet said it could be allergies or Pemphigus (autoimmune). We can’t afford the biopsy cost right now so we’re doing a round of antibiotics and steroids for the week to start. We’ve also starting switching him to hydrolyzed kibble and hypoallergenic duck and rabbit wet food from Royal Canin at recommendation from the vet.

I really would love if food changes were the culprit but I’m so fearful this will be a lifelong battle and the long term steroid use will give him diabetes or other conditions.

I’ve seen a couple people post that diet changes helped heal their cat’s skin issues but any positivity is welcome!!