3 years of red irritation on penis PLEASE HELP!! NO STD OR UTI

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This irritation appeared around 3 years ago when one day I noticed a small bit of skin peeling. It then got very red and has stayed like that since. It flares up more after masturbation.

I recently went to a dermatologist who diagnosed it as dermatitis and gave me Eucrisa topical cream to put on it for a few weeks. It has helped the inflamation a bit, but it is still VERY IRRITATING. Could this possibly be a yeast infection, or something else?!

*The irritation feels like a burning sensation and hurts more when in contact with underwear or clothing.

sti tests? herpes?