How to get rid of head lice when treatment fails
If you recently used a lice-killing shampoo or cream rinse, it may have failed to work. This is happening in homes across the United States, leaving parents feeling anxious and worried.
Why head lice treatments fail to work
For years, parents have been buying these non-prescription shampoos and cream rinses. Because the active ingredients have remained the same all these years, new generations of head lice have become immune to them. Once lice become immune, the product no longer works. Scientists call this resistance.
Effective treatment for head lice is available
If a head lice treatment that you can buy without a prescription fails to work, the CDC recommends that you see a health care provider. Highly effective prescription treatments that you apply to the scalp are available.
The Food and Drug Administration (FDA) has approved prescription treatments for children as young as 6 months of age.
The prescription treatments work because they contain different active ingredients than the non-prescription shampoos and cream rinses.
If using a prescription treatment worries you, it may help to know that today’s non-prescription lice medications were once only available with a prescription. You can also take comfort in knowing that each of the newer prescription treatments was tested in clinical trials. Before the FDA approved each of these treatments, it was shown to be safe and effective for children.
Using extra amounts of lice medication can be harmful
The Centers for Disease Control and Prevention (CDC) warns that using extra amounts of lice medication can be harmful and you should only do this if your doctor or pharmacist recommends it.
Natural products can give parents false sense of safety
If using a natural product or one that you can buy without a prescription makes you feel safer, you should know that researchers have found many of these treatments can be harmful.
While studying lice-killing products that you can buy without a prescription, researchers found the some of these products contain:
Acetone (often found in nail polish remover)
A spray often used to lubricate metal
None of the above has proven effective in killing head lice, and the American Academy of Pediatrics (AAP) says that these ingredients “present an unacceptable risk to the patient.”
Using an herbal product can also be risky. While these products come from plants, research shows that some chemicals which plants make to protect themselves from insects and other pests can be toxic to humans.
We don’t always know which of these chemicals are toxic because the FDA does not regulate herbal products.
Home remedies can also be problematic. You may have heard claims that petroleum jelly, mayonnaise, butter, margarine, or olive oil can suffocate lice. None of these has been found to be effective. What may be happening is that these remedies make the lice less active for a while, which gives people the impression that the lice are dead.
A dermatologist can treat your child safely and effectively
For these reasons, the CDC recommends seeing your health care provider.
Seeing a board-certified dermatologist can be helpful because these doctors specialize in diagnosing and treating conditions that affect the skin and hair. Their expertise helps you to get an accurate diagnosis.
This is important. Researchers have also found that another reason non-prescription head-lice treatments fail to work is that the child doesn’t have lice.
Lice are small and fast, so they can be hard to see. Sometimes parents — and even medical professionals — mistake another medical condition for head lice. An allergy or irritated skin could be causing those itchy, red bumps and flakes on your child’s scalp.
If your child has head lice, a dermatologist can tell. A dermatologist can also recommend an effective treatment for your child. This may be one of the prescription treatments.
Sometimes, simply combing your child’s hair to remove the lice and nits (eggs) can be effective. While time-consuming, studies show that combing injures the lice, so they rarely survive.
When it comes to removing lice by combing, technique is crucial. By seeing a dermatologist, you can learn the right technique and other tips for getting rid of lice.
Seeing a board-certified dermatologist can also help you feel that your child is in good hands, which can reduce the anxiety and worry you feel.
Related AAD resources
Head lice: Diagnosis & treatment - At-home and prescription treatments for head lice
American Academy of Dermatology:
“Head lice bugging your family? Dermatologists’ tips for getting rid of lice.” News release issued Feb. 12, 2013.
Bedbug, scabies, and head lice — oh my.” News release issued Mar 4, 2010.
Centers for Disease Control and Prevention. “Head lice: Treatment.” Page last updated 8/19/2016.
Devore CD, Schutze GE; American Academy of Pediatrics, Council on School Health, Committee on Infectious Disease. “Head Lice.” Pediatrics. 2015;135:e1355-1365.
Koch E, Clark JM, et al. “Management of head louse infestations in the United States — A literature review.” Pediatr Dermatol. 2016;33:466-72.