Hello Doctor
In the last one month or so I have had two bumps near the groin area which were small to the size of a 3mm and they were a bit painful and lasted for a week or 10 days and they faded away, leaving little dark patches. while these were almost faded I had one underneath my belly button that also lasted a week and then started fading away. After a week or so and later it started to expand again its like 1 cm now. The issue is its in buckle area.
Background: I go to gym also use steam and dry sauna. The first two bumps faded when I was irregular to gym and sauna for a week (may be 2 days in a week). the current bump also faded i believe during this phase but might have become re-activated when I re-started my excercise + hot sauna (180F) routine. I generally do 15 mins of walk + excercise for 75 mins weights + steam sauna 8 mins + hot sauna for 10 to 15 mins.
Also kindly note that I use gym towels. but never wipe near groin area with those towels.

My questions : from the pictures attached are these hair or sweat gland bumps or are they something else.