What Causes Red Rashes At The Head Of The Penis?

Hi there, for the past few months i have noticed small red blemishes appearing on the head of my penis, it is itchy at times but not that often. It goes away and comes back from week to week. I have had unprotected sex in the past but i think it may be more of a fungal thing? I shower daily and have a high standard of cleanliness. My girlfriend has recently complained about tenderness around her vaginal opening and slight itchyness but only after we have sex, then again like myself, it goes away. can you help?