It's an infection of the skin the bacteria that is always present on the surface , finds a Hair follicle

to move in grow and die , the dead bacteria buisd up . ind that is perhaps, that cyst/carbuncle..


Have a Dermatologist to consult ? I'm just a guy that has ridden my bike on long tours

Clean skin and clean bike shorts Daily were found to keep my backside comfortable , even on a Brooks saddle ..