$ perl -MTest::More -e 'ok (/\b\p{XPosixAlpha}+\b/, "$_ matches") for (qw/A Z Å Ä Ö/); done_testing();'
ok 1 - A matches
ok 2 - Z matches
ok 3 - Å matches
ok 4 - Ä matches
ok 5 - Ö matches
1..5
$