Like Dan said, definitely not a collocation or even a commonly used phrase or idiom

A couple of things. Your question should be: Is this collocation used nowadays or not? As far as I know, this is not a collocation. He's literally talking about someone being prone (likely to get) boils.

This is something intended for a specialized audience, perhaps doctors or nurses. Whether or not the term is commonly spoken does not matter. When speaking to a specialized audience, the important thing is accuracy, not the popularity of the language you use.