I remember reading a horror story many years ago which featured a man who had various creatures living inside him. One was a sort of spider called 'Mother', and i remember her crawling out of his nose at one point while he was locked in a room, which might've been in a mental institution.
This story was part of a short story collection which included a story by the author Dean R Koontz. I think this story may've been by Robert Bloch, but internet searches have drawn a blank.
After typing this I remembered that Clive Barker wrote the intro to the book, which i've now found out was 'Night Visions 4' and the story i'm thinking of is called 'Best friends' by Robert R McCammon. The three creatures were called Adolf, Frog and Mother.