You're getting the repeat because the %items hash isn't unique for each of the "$scottnum". You can fix it easily by putting an undef %items after you print out the hash.

    if (($item[0] ne "") && ($item[1] ne "")){ 
      $items{"$item[0]"} = "$item[1]"; 
      foreach my $key (keys %items) { 
        print "$scottnum\t $key \t $items{$key}\n"; 
      } 
      undef %items; 
    }
[download]

But this probably isn't what you wanted. You probably wanted a hash with a key and a subkey (a hash of hashes). I'm not good at explaining so let me show you instead:

while(<DB>) { 
  chomp; 
  @record = split(/\t/); 
  $scottnum = $record[0]; 
  @details = split(/\|/, "$record[1]"); 
  foreach $detail (@details) { 
    @item = split(/,/, "$detail"); 
    if (($item[0] ne "") && ($item[1] ne "")){ 
      ###########################################
      $items{$scottnum}{"$item[0]"} = "$item[1]";
      ########################################### 
    } 
  } 
} 
foreach my $scottnum (keys %items) { 
  for my $key (keys %{$items{$scottnum}}) { 
    print "$scottnum\t $key \t $items{$scottnum}{$key}\n"; 
  } 
}
[download]

This way a hash of hashes is created.

Stylistically, I would have probably done it something like:

my %info; 
 
open(DB, "db.txt") || die "Could not open the database: $!"; 
while (<DB>) { 
  my @info=split /[\s|,]+/,$_; 
  my $scott=shift @info; 
 
  while (my $key=shift @info) { 
    $info{$scott}{$key}=shift @info; 
  } 
} 
close DB;
[download]

But you are definately on the right track!