After upgrading to Node v.10.9.0 via Homebrew the following error message was thrown from PHP:
dyld: Library not loaded: /usr/local/opt/icu4c/lib/libicui18n.61.dylib
Referenced from: /usr/local/bin/php
Reason: image not found
Reinstall PHP to fix, for me that's:
brew reinstall [email protected]
For me, "brew reinstall icu4c" configured and "make"-ed php7.1 for the newer icu4c.. problem solved! :)