Sunday, June 19, 2011

Lice Treatment Warnings

Before using any product or treatment, you need to determine whether it’s appropriate in your specific situation. A head lice treatment may be appropriate and safe for one person, but carry unacceptable risks for another person of a different age or health status.That’s why it’s so important to consult your own doctor, before beginning any treatment. While I was researching head lice treatments, I found information that surprised me about possible health risks associated with ingredients in certain head lice products and home remedies.
I include a few examples on this page to demonstrate why it’s important to do thorough research.
The following examples are NOT comprehensive or complete. Always consult your doctor before starting any treatment.


People can become allergic to any ingredient in any product. If someone in your family has allergies, then you probably already know how important it is to read ingredient lists carefully for known allergens. Even if there are no known allergies, products containing common allergens should often be tested by limiting exposure to only a very small amount at first, in a limited area, to see if a reaction occurs. Your doctor can advise you on this.


NEVER use plastic wrap to cover kids’ hair. Use a shower cap or towel. Plastic wrap and plastic bags pose a suffocation risk.


Pesticides are not necessary to deal with head lice, and they should not be used on children. (You can get rid of lice and nits by combing alone. The only reason to use pesticides or any other product other than a good nit comb is to make the process easier and/or quicker … a potential benefit that does not justify the risk of putting pesticides on a child’s head.)


According to an FDA Public Health Advisory, Lindane puts patients “at risk for serious neurologic adverse events, and even death, particularly with early retreatment”.


According to the Journal of Pesticide Reform, permethrin “is a neurotoxin. Symptoms include tremors, incoordination, elevated body temperature, increased aggressive behavior, and disruption of learning. Laboratory tests suggest that permethrin is more acutely toxic to children than to adults.”

Pyrethrins and pyrethroids

According to articles published at the National Institutes of Health, pyrethrins and pyrethroids “can induce adverse health effects, more often in acute poisoning, but also due to chronic exposure.”


According to an article posted by the National Pediculosis Association, malathion is “chemically related to nerve gases developed during World War II. For decades, scientists have been debating whether such pesticides cause birth defects, cancers, and other health problems. Studies have shown links between regular exposure to malathion and various human maladies, including non-Hodgkins lymphoma, childhood leukemia, anemia, chromosome damage, and weakened immune systems ... Malathion and other pesticides are especially dangerous to children, who are more vulnerable to neurotoxins than adults.”


It’s probably never appropriate to apply an alcohol-based product to a child’s scalp and let it sit for any length of time. I would certainly never do this without asking my doctor first. For instance, trying the Listerine home remedy would likely not be safe for kids.

Coal Tar

I’ve seen Denorex and other coal-tar shampoos recommended as effective for treating and preventing head lice infestations. However, coal tar in high concentrations is classified by the World Health Organization as a cancer-causing agent. So, while I might consider using a coal tar shampoo once to fight a lice infestation, I would not use it regularly for anyone in my family.

Essential Oils

Lots of lice products contain essential oils. These are intended either to smother/kill lice, or simply to repel them. Often the marketers of these products promote them as totally safe to use, even on babies and young children.

However, many essential oils are not well studied. Some of them may well be safe to use frequently … but because they haven’t undergone rigorous controlled testing, it could be there are subtle harmful effects that haven’t been discovered yet.

Tea Tree Oil & Lavender Oil

For example, during my research into lice products I discovered that according to the National Institutes of Health, tea tree oil and lavender oil may have subtle hormonal effects when used long-term.

So, while I might consider using a product containing tea tree oil as a one-time event to treat head lice on my son, I would definitely not have him use a tea tree oil shampoo regularly in order to prevent head lice.

Eucalyptus Oil

According to the University of Maryland Medical Center, “Eucalyptus oil should not be applied to the face or nose of children under age 2. People with asthma should use eucalyptus oil with caution due to the herbs' potential to trigger an asthma attack. Pregnant and breastfeeding women should not use eucalyptus.”

Peppermint Oil

According to the American Academy of Family Physicians, “Peppermint oil should not be used internally, or on or near the face, in infants and young children because of its potential to cause bronchospasm, tongue spasms, and, possibly, respiratory arrest.”

Rosemary Oil

According to Baby Centre, pregnant women should not use rosemary oil at all as it may be harmful.

Mineral Oil

According to The American Head Lice Information Center, “mineral oil (including baby oil) is not recommended because it can be harmful to mucous membranes”.


Do not leave mayonnaise on a child's head overnight; it will turn rancid and the child could accidentally consume some of it.


Pregnant women should check with their doctors before applying any treatment for head lice (either to themselves or to kids).

Oil and Petroleum

If you use a remedy with oil or petroleum products in it, you may need to shampoo the hair several times with clarifying shampoo or dishwashing liquid to wash all the oil out.

What do they look like?

What do they look like

  • Tiny, wingless insects that move quickly and are difficult to see
  • 1-2 mm long and greyish brown in color
  • Nits (eggs) can sometimes be mistaken for dandruff

Common sites where head lice are found

Commonly found around ears, forehead and nape of neck. Lie close to scalp.

Important things to remember

  • Lack of cleanliness does not cause head lice
  • Both children and adults can get it
  • Short hair does not prevent the spread
  • Lice do not live on cats, dogs or other animals
  • You cannot prevent head lice by using head lice shampoos or products - use only if lice are present and as directed
  • Be sensitive to your child’s feelings!

Head lice treatments

    Talk to your doctor:Head lice treatments

  • if you are pregnant or breastfeeding
  • before treating children under the age of two
  • if a person has a seizure disorder
  • if the skin of the scalp has an infection

  • There are many products available at your pharmacy (talk to your pharmacist)
    • Buy a head lice shampoo or cream rinse from your drug store
    • Apply as instructed. Misuse and overuse could be hazardous
    • The products kill the head lice and many eggs, but a second treatment is needed 7 to 10 days after the first treatment to kill any newly hatched lice before they mature
  • Remove all nits by using fingernails or a nit comb
  • It is suggested that you limit shampoo use between the two treatments and in the week following the second treatment. This may allow the head lice product to work more effectively.
  • Check head for live lice daily between treatments and remove any nits that are still present (do this in bright light)
    • head lice and nits are commonly found around ears, forehead and nape of neck - check these areas carefully
    • If live lice are found in the days following the first treatment, consult your pharmacist or call 416-338-7600
  • Check all close contacts (i.e. family and friends)
  • There is conflicting information concerning whether or not all nits should be removed after the application of head lice products
  • Toronto Public Health recommends the removal of all nits as:
    • head lice products are not 100% effective
    • removal of nits may minimize the hatching of eggs that were not killed and the spread of young hatched lice to other heads
    • it is easier to notice a new infestation if all nits are removed
  • If a baby or a woman who is pregnant or breastfeeding has head lice:
    • Call your family doctor or Motherisk Program of the Hospital for Sick Children at 416-813-6780 for advice before choosing a head lice treatment product
    • If pregnant and treating others, wear plastic or rubber gloves

Life cycle of head lice

Life Cycle consists of three stages:
  • Nits (eggs)
    • oval, usually white in color, may be mistaken for dandruff, are firmly attached to a hair shaft, close to the scalp
    • take about 1 week to hatch into nymphs
  • Nymph (baby louse)
    • lives on scalp and feeds off human blood
    • matures in 1 week into an adult louse
    • if a nymph falls off a person it usually survives only one day
  • Adult Louse
    • size of a sesame seed, has 6 legs, and is tan to grayish-white
    • females lay nits - they are usually larger than males
    • can live up to 30 days on a person’s head
    • feeds on human blood
    • if a louse falls off a person, it may survive one to two days

Should the house be disinfected if someone has head lice?

Because head lice don’t live long off the scalp, there is no need for extra cleaning.
To get rid of lice or nits from items like hats or pillowcases:
  • Wash the items in hot water and dry in a hot dryer for 15 min; or
  • Store the items in an airtight plastic bag for 2 weeks.