Hi, My Armpits Have Been Irritated For A Few Months

Hi, my armpits have been irritated for a few months now. It started after I went swimming and took a shower after, but in the lat 2 months it's been at its worst. Any sort of moisture will irritate it, whether it be water, walking outside in the humidity, or sweat. There's no redness or anything visible on the surface. My doctor gave me and anti-fungal ointment but it offered no relief. Wondering if you'd be able to offer any insight as to what could be causing this. -thanks