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 php@7.1
In my case, reinstallation php@7.1 didn't work. I downgrade the icu4c from 67 to 64 by this document