weird bump/blister on toe with dark spot in center?

About a week or so ago, I noticed a shiny red bump on the second toe (next to my big toe) of my left foot.
I’m not sure if this is related to it, but I have had what my dr. calls a “blocked oil gland” on my upper thigh about a month ago, which is annoying and tends to come and go. However, two days ago I noticed a dark spot in the center of the bump that seems to have gotten slighter darker and bigger by today. I didn’t have this spot with the blocked oil gland. Do you have any idea what this thing could be?Any advice is appreciated. Thanks!