Suggest Remedy For Rash Due To Itching Caused By Catfish

I had an allergic reaction a couple of weeks ago to catfish, i started itching and my armpit was itching as well and i just kept scratching it, later that night i noticed that i had scratched so hard apparently that some of the skin came off and ever since then its been worsening....today i had developed what looks like a red rash, i went the pharmacist and he told me to get tinactin athletes foot spray and use it twice a day and this was tuesday and today i have noticed the rash