Can a fungus like athletes foot take root in perineum area? as an avid cyclist/swimmer/runner i think it arises. what to do to get rid of it?

Jock itch: [although you don't have to be a jock to qualify]. Fungus loves moisture. Change out of damp garments. Dry well. Use powder [not corn starch]. Wear loose clothes which breathe [like cotton]. You can use over-the-counter athlete foot's cream. Boric acid is an old fashioned remedy that works too.

Not really.Dry,cream: Fungus is all over your body. When an area of the body stays wet for a long time, it can proliferate. So it is not really spreading...Just popping up in different places. Prevention is key; try to keep the area as dry as possible. Shower immediately after exercise and dry well; use powders to absorb moisture. If the infection takes hold, use topical creams first-line.

A fungus can: Lie anywhere on the body. Skin is skin. If indeed it is fungus an antifungal should work. The problem you may have is figuring out a way to prevent it from coming back particularly if you feel you are getting it from cycling. Ssee a dermatologist to confirm the diagnosis as that is a difficult anatomical region to self examine.