Cleaning your House After Lice
CDC does not have clear scientific evidence to determine if suffocation of head lice with mayonnaise, olive oil, margarine, butter, or similar substances is an effective form of treatment.
If the treatment for head lice doesn't seem to be working, does this mean the lice are resistant and I need a different treatment?
The following are several common reasons why treatment for head lice may fail sometimes:
- Misdiagnosis. The symptoms are not caused by an active head lice infestation.
- Applying the treatment to hair that has been washed with conditioning shampoo or rinsed with hair conditioner. Conditioners can act as a barrier that keeps the head lice medicine from adhering to the hair shafts; this can reduce the effectiveness of the treatment.
- Not following carefully the instructions for the treatment that is used. Some examples of this include not applying a second treatment if instructed to do so, or retreating too soon after the first treatment before all the nits are hatched and the newly hatched head lice can be killed. Another reason is retreating too late after new eggs have already been deposited.
- Resistance of the head lice to the treatment used. The head lice may have become resistant to the treatment. If the treatment used does not kill the head lice, your health care provider and pharmacist can help you be sure the treatment was used correctly and may recommend a completely different product if they think the head lice are resistant to the first treatment.
- Reinfestation. The person was treated successfully and the lice were eliminated, but then the person becomes infested again by lice spread from another infested person. Sometimes reshampooing the hair too soon (less than 2 days) after correctly applying and removing permethin can reduce or eliminate any residual (continued) killing effect on the lice.
Is there a treatment recommendation for certain age groups?
Before treating young children, please consult the child's doctor, or the health department for the recommended treatment based on the child’s age and weight.
Are there any side effects from using these chemical treatments for head lice?
Treatments for head lice are generally safe and effective when used correctly. Some treatments may cause an itching or a mild burning sensation caused by inflammation of the skin on the scalp. Most products used to treat head lice are pesticides that can be absorbed through the skin. Therefore, all medicines used for the treatment of lice should be used with care and only as directed.
Is it necessary to remove all the nits?
No. The two treatments 9 days apart are designed to eliminate all live lice, and any lice that may hatch from eggs that were laid after the first treatment.
Many nits are more than ¼ inch from the scalp. Such nits are usually not viable and very unlikely to hatch to become crawling lice, or may in fact be empty shells, also known as casings. Nits are cemented to hair shafts and are very unlikely to be transferred successfully to other people.
However, parents may choose to remove all nits found on hair for aesthetic reasons or to reduce the chance of unnecessary retreatment.