An inflamation of one's nut sack. Bagsiosis is characterized by red, itchy, bumbs resulting in sack dandruff and uncontrolable scratching of the scrotum. If untreated, Bagsiosis can lead to full-on Ballrot.
Man, I got a scorching case of Bagsiosis! My balls are gonna rot off if I don't rub some ointment on em!