What Causes Fluid Filled Blisters On The Thighs And Armpits?

I have what I belive is a skin tag on my inNer thigh I have also developed a few of these tags in my arm pit however the one on my inner thigh has become irritated I assume from the constant rubbing when I walk. Now that it has been irritated it is painful and the appearance has changed from a skin colored extra piece of skin to a red bubble that appears to be filled with fluid. My concerns are the pain and if this is something more serious than just a skin tag. I have taken a picture of it but don t anywhere I can attach the photo. Is there anything I can do for this at home or do I have the schedule an appointment with a dermatologist?