Today I Masturbated And Showered, A Few Hours Later I

Today I masturbated and showered, a few hours later I noticed a few patches of raised skin on my outer foreskin on the penile shaft. It had many tiny scabs. The scabs were the size of a needle point and clustered in a horizontal fashion with another patch a little bit above it. The patches almost seem to fit the grip of my dominant hand. I recently have taken a course of antibiotics for hair follicultis. And now I am applying ketoderm and canestan to combat the yeast overgrowth. I never noticed any blisters or redness prior. Just the scabs today. My main question would be why would this happen? Is it due to antibiotic use or any of the creams?