Pearls, like lycanthropy, are a medichine glitch. Fortuitous for some but harrowing episodes in body horror for most, the glitch causes loose material to conglomerate and slowly form pearls, just as in oysters and mussels. Unless the medichines are checked, infection is unnoticeable for the first month, but then the pearls reach significant sizes, beginning to to rub against each other and apply pressure to surrounding tissues.
Pharmed pearls have maintained an appeal despite nanofabrication. Many claim that fabbed pearls simply don't have the same smooth iridescence. The medichines of pharmers are programmed to only allow pearl growth just under the skin, from where they slowly emerge until they can be removed. Medichines are also recommended to accelerated pearl growth, for their use in healing over the craters left from removal, and to deaden the pain of what are essentially whole-body corns.
Victims of pearls suffer 1 SV daily due to pain, +1 SV per month infected.