Head lice infestations are annoying episodes that commonly occur in the school and daycare settings and can affect anyone regardless of personal cleanliness. These infestations tend to happen in the months when school starts in the fall between August and September. Head lice infestations are generally harmless because lice do not directly spread diseases but the itching and scratching make you miserable and can lead to infections from breaking the skin on the scalp. For this reason we have assembled a guide to head lice and how to approach the problem. If you have any further questions or comments about the information presented here then you should consult your pharmacist.
Lice are tiny blood sucking insects that leave an itchy wheal when they bite the scalp. They do not jump like fleas or fly like other insects. A louse egg is known as a nit and hatches after 10 days and lice reach maturity in about 10 days after hatching. Mature lice continue to lay eggs and keep the infestation cycle going unless treated and removed.
A Closer Look
Inspecting the head is very important in finding and treating head lice. The best places to look on the head are the top of the head, near the ears, and the base of the neck. Adult lice are very small and can be difficult to spot because they move around, but the eggs or nits are easier to see. The eggs will have a greyish color to them and hatched eggs will appear white. When looking for eggs you should part the hair and look for eggs which are usually attached close to the bottom of the hair shaft. Lice eggs are not similar to dandruff or dirt because the eggs will be firmly attached to hair shafts and won't move around easily. Thoroughly combing through wetted hair with a special fine toothed comb known as a nit comb can also help you spot the eggs and potentially remove some lice and nits. A nit comb alone is not enough to treat head lice though.
When to Consider Treatment
You should only consider getting medication to treat head lice after you have visibly identified lice on the scalp such as crawling adult lice or visible nits. If the itching and scratching has caused an infection on the scalp then the broken skin will appear to be swollen and red and you should go to the doctor instead of treating the lice on your own. If the eyelids or eyebrows have lice then you should not treat on your own and seek a doctor instead. Additionally, if the patient has an allergy to chrysanthemums or ragweed then you should consult a doctor instead of treating it yourself.
OTC (Over the Counter) Options
There are two main OTC head lice medications: pyrethrins (brand name RID) and permethrin (brand name Nix). These agents do not require a prescription and are available commonly as shampoos, foams, creams, or gels. In general these agents are applied to wet hair and left on for 10 minutes before being rinsed off and then a second treatment is done 7-10 days after the first time. Use a nit comb each day on wet hair after treatment to check and remove dead lice and eggs; if there are no dead lice after a day then you should consult your pharmacist or doctor. If the instructions on the bottle are different from this then follow the bottle instead. Do not use normal shampoo or conditioner before you apply the medicine. Make sure to apply the head lice medicine to all of their hair and not just the scalp; you might need more than one bottle if they have longer hair. Make sure to avoid contact with the eyes and face when applying the medicine and when rinsing it off because it will irritate them; flush the eyes with water immediately if medicine contacts them. Do not use the medicine again within 1-2 days after using it the first time, you need to wait for 7-10 days to kill the most lice. Pyrethrins (RID) should only be used in children at least 2 years old while permethrin (Nix) should only be used in children at least 2 months old. Both of these drugs are safe with proper use and the most common side effects are mild irritation, redness, or itching on the scalp that can last a day or two. Do not use them both at the same time and do not use more than needed at a time.
In addition to OTC medication treatment it is important to consider non-medication related steps in order to minimize head lice exposure and prevent reinfestation and spreading head lice to others. Avoid direct physical contact with someone with head lice when possible and do not share combs, hairbrushes, towels, caps, hats, or any other accessories that contact hair. Lice spread through contact with infested hair or objects in contact with infested hair. Consider cleaning any items the patient has contacted within the past two days. Clothing and bedding should be washed in hot water and dried in a dryer to kill lice and their eggs. Combs and brushes should be soaked in very hot water for 10 minutes. Items that cannot be machine washed should be sealed in a plastic bag for two weeks to kill lice; they cannot survive without a human host. Carpets and furniture should be thoroughly vacuumed. Insecticide sprays for cleaning objects are not required because lice will die without a human host. The general rules for killing lice is high heat, drying them out, or isolation.
When OTC Isn't Enough
You should follow-up head lice infestations within 4-10 days of applying the second treatment of the chosen OTC medication by examining the scalp, preferably with combing through their entire wetted scalp with a nit comb. Lice can be resistant to some treatments so check with your pharmacist or doctor if there are still signs of lice infestation. If this occurs a doctor can provide more information and potentially write for prescription-only head lice medication. There are several different options available that we will list here:
Benzyl alcohol lotion (brand name Ulesfia)
Ivermectin lotion (brand name Sklice)
Malathion lotion (brand name Ovide)
Spinosad topical suspension (brand name Natroba)
Several old folk remedies exist with questionable effectiveness for treatment. Oil-based products such as petroleum jelly, butter, olive oil, and mayonnaise do not have any lice or egg killing properties and are not recommended. Some home remedy recipes call for various combinations of essential oils such as tea tree oil, lavender oil, anise oil, and others. These products do not have to meet effectiveness, safety, and manufacturing standards of normal drugs because they are not regulated by the FDA (Food and Drug Administration) and thus are not recommended. Gasoline and kerosene are not to be used because of toxicity, flammability, and lack of effectiveness. Even though drying out lice and eggs can kill them it is not recommended to use a household hair dryer for this purpose; there is a special machine that applies heat to the scalp to kill lice called a LouseBuster but this treatment is only available at specialized clinics and not for home use.
Lice are spread from contact with infested hair or from objects in contact with infested hair
Don't share hats, combs, towels, and other hair accessories with infested individuals
Always check for lice and eggs before you start using medications
You can use OTC and non-drug approaches if you qualify for self-treatment
If the above does not work, consult your doctor or pharmacist
Avoid alternative therapies and folk remedies