Has anyone else had the same problem my sister is having?

my sister, the other day, had a pimple/ scab looking thing on the inside of her armpit, she picked at it and she said there was a lot of dried skin on the top but when she got it off she pulled out something white and stringy (like a bean sprout) with a pair of tweezers. she said it didnt look like puss. could it have been some type of bug, or bacteria, or something?? has this ever happened to anyone else?