Localized swelling at the proximal base of the fifth metatarsal. Stress Fracture?

I have a small section at the proximal base of my fifth metatarsal that is somewhat swollen and slightly red (about the size of a Nickel). This is on my 'primary' foot; the one that I pivot on frequently. There is no pain, no tenderness with direct pressure, foot movement, or walking. I have also looked at it closely to try to determine if there is an insect bite, but I did not find any evidence of such. It seems to have come on suddenly. I did a bit more walking than usual on the day prior to it being visually noticed. Is this possibly a stress fracture (even with no pain)? Thanks!!

[Yena H Do, DPM]

stress fractures usually are painful.  if you pivot, run, jump, or stand on the tiptoes and still don't have pain, it is not likely a stress fracture.  if it is a localized red bump, it may be an insect bite.  apply calamine lotion to the area.  if it continues, apply a cortisone cream.  
icing can help as well.  if this continues to appear, have it checked my your doc.