The diagnosis of louse infestation is usually based on the presence of eggs, and the success of treatment on their removal from the hair.  However, dead eggs and eggshell (nits) are frequently found on hair for months after lice have been successfully removed by treatment.  Examination of the scalp by hand or by parting the hair with a screening   stick, may easily reveal the presence of these nits, which often leads to a false positive diagnosis.  Therefore, a fine-toothed louse comb should be used, which  is far more reliable for detecting living lice than hand examination.  In addition, a louse comb can be used: (a) for the prevention of louse infestation by suppressing the establishment of lice on the scalp after the initial infestation; (b) as an accessory tool to any anti-louse treatment method; (c) for the treatment of a long term head louse infestation; (d) for verification that treatment with a pediculicide was successful; and (e) for the removal of nits.