PHP Mail header for emails with special characters in the subject or message

My code:

$to      = 'example@example.com';
$subject = $_REQUEST['subject'] ;
$message = $_REQUEST['message'] ;
$header = "From: noreply@example.com\r\n"; 
$header.= "MIME-Version: 1.0\r\n"; 
$header.= "Content-Type: text/html; charset=ISO-8859-1\r\n"; 
$header.= "X-Priority: 1\r\n"; 

mail($to, $subject, $message, $header);

When i send a mail with special characters such as ®ð-˚©-ʼ“æ,˚ˍðß©, in the message, it works but spacing is no longer dealt with (every new line or space gets removed) And the second problem is that the special characters are not displayed in the subject. They just output like: øʼªʼ

Thanks in advance!