Please if you know what this could be, let me know. Its on my husbands knee, its been here for about 4 days and its painful but won't pop like a pimple. The area around the bubble is red and lifted like a lump. But the pimple looking bubble only appeared 2-3 days after the redness. I was thinking maybe an ingrown hair? but my husband has said its painful and ever rubbing on clothes makes it sore. We are going to see a doctor at the end of the week if its still there but just thought maybe someone has a similar story? thankyou!!!

Pic #1 is with the flash on.

Pic #2 is with the flash off and in the light.