It looks like Fink is a bit behind the Erlang releases. Here's an erlang-otp.info file and an erlang-otp.patch file. You can put these in /sw/fink/dists/unstable/main/finkinfo/languages and then do a fink install erlang-otp . I'll ping the maintainer to get these added to Fink.
When you fink install these right now, you'll get prompted because the tarballs are not on the fink mirrors, so you'll have to select "download from original source URL".
Update: if you have pcre installed it can confuse the build. You can use erlang-otp.info.pcre instead. Rename this to erlang-otp.info in the /sw/fink/dists/unstable/main/finkinfo/languages directory.