Buttcrack problem!

[Mp70177]

I'm having a problem in my Gluteal Cleft  (buttcrack). Last week I had a but of diahrea and the next morning I woke up with intense itching in my crack, I ignored it thinking it must be yeast (my hormones have been out of whack). The next day I had a a rash in the entire cleft, extending out a bit on each side. Probably a inch above my anus in the cleft, it looks and feels as if the skin split (spreading the butt apart makes it look round, but resting it's literally down the center line). It's not really bleeding, painful to touch. I've been treating with antifungals, cortisone and also zinc oxide (as well as keeping clean) . Its definetly getting better, not itching only sensitive to touch now - it's been 9 days since it showed up.  
The split or sore looks whitish. It's not goopy looking like herpes pictures online, but it does have some clear fluid to it, which I know is lymphatic fluid. It's still open, but tonight I'm not putting any creams on it and letting air be the treatment.
What I'm wondering, what could be the cause of this? I have ulceritive colitis, could it be likely that I'm getting skin sores now?  Or is it more likely to be herpes  (which I doubt, I test in April for it and was negative) ? I have had this problem before when I had issue with hormones but never took the time to look at my crack, just remember how it felt .

[purple1234567]

It's always best to get a doctors opinion on what something like this could be- if it's getting better though, I wouldn't be overly concerned.  

[Mp70177]

Update : while my topical treatment of antifungals andnhydrocortisone helped, the skin opening was still there. I went to the Dr this morning. I was told it is a Pilondiak Cyst and was prescribed bactrim. They told me it definetly does not look herpetic at all and said that these cysts are actually quite common.