Super lice are infestations of head lice that do not respond immediately to the usual commercial products formulated to remove the lice from the hair. Over the years, there are those in the medical community that warned that it was only a matter of time before these lice came to be. Other medical professionals reject the concept, and believe the resistance has more to do with the individual than with the lice.
The theory behind super lice is that over time, strains of lice have built up an immunity to the key ingredients in over the counter lice removal products, such as shampoos. Proponents of the theory note that it is not unusual for any type of insect to acquire an immunity to a given product over time, and that there is no reason to assume lice are not capable of that same level of adaptation.
There are several different chemicals used in various lice removal products. All of them are considered to be insecticides. Such chemicals as permethrin, lindane, malathion and pyrethrin are found in either over the counter remedies for head lice, or are part of the compounds of prescription only products formulated to deal with severe cases. Lice that are classified as super lice often require treatment with the stronger prescription products, even if the infestation is considered to be somewhat minor in the number of mature lice and eggs present.
These treatment resistant lice do still respond to over the counter products in some cases. However, rather than the usual course of initial treatment followed up with a treatment several days later to kill any lingering eggs before they hatch, dealing with super lice usually means additional applications of the product over a longer period of time.
While some researchers are firmly behind the idea of super lice, others consider the whole idea to be a misrepresentation of the situation. As part of the process of debunking the concept of super lice, they point to the fact that many people still receive relief from using over the counter lice removal products. However, there is a growing concern in some circles that if newer and stronger treatments for lice are not developed, the lice will continue to adapt and eventually render the current treatments completely ineffectual.