Possible treatments include: combing the hair frequently with a fine tooth comb or shaving the head completely.  A number of topical medications are also effective, including malathion , ivermectin , and dimethicone .  Dimethicone, which is a silicone oil , is often preferred due to the low risk of side effects.  Pyrethroids such as permethrin have been commonly used; however, they have become less effective due to increasing pesticide resistance .  There is little evidence for alternative medicines .