Supposedly In The Mouth of Madness feels that way for a reason! When it came out, there was a lot of talk about how Carpenter had been in negotiations to buy the rights to a Clive Barker series that took on the Lovecraft mythos, but was denied. I think it was Book of Blood series. So Mouth of Madness was apparently made as an 'homage'.

I don't know how true the bit about wanting to do it and being denied is, but there are definitely a lot of homages and references and whatnot to Barkers work. What with Barker and Carpenter being friendly and even at one point planning to make a movie together, it makes sense to me.

It's a super fun movie, though! I watch it every Halloween season. :D