Head lice is the common name for the species pediculus humanus capitus. These creatures are a type of ectoparasite, or parasites that live on the outside of your body, which feast on blood several times each day. These lice like the scalp because of its warmth. The type of head lice that humans get do not lives on any other animal. There are 3 stages of the lifecycle of head lice: nits, or small yellow/white eggs that often are found in the hair one-quarter inch away from the scalp; nymphs, or the first stage out of the egg where they are the size of a pinhead; and tan to gray/white adults that are the size of a sesame seed.
How do they get from one person to another?
The spread of head lice is most commonly from head-to-head contact between people. This most commonly occurs in children during sports, on the playground, during slumber parties, etc. Rarely, lice can be spread via contact with hats, scarves, combs, or using linens that an infested person used. People who are infected often do not know for the first few week. Head lice are NOT spread because of poor hygiene.
How do I know if I have head lice? (symptoms)
Unfortunately, for the first few weeks of infection with lice, many people do not have any symptoms. When symptoms do occur, people experience itching of the scalp. Sometimes, people also can sense the lice moving within their hair. In smaller children who have a harder time saying what exactly is bothering them, they maybe become irritable or more sleepy. Luckily, head lice do not transmit any other type of disease. This means that they are more of a nuisance than an illness. If you suspect you or your child has lice, have someone look over the scalp to see if they can identify any eggs, nymphs, or adult lice. If you are unsure if what you are seeing is lice or not, go to your doctor to get checked out.
The main treatment is over the counter permethrin or pyrethrin, that will be repeated 9 days after it is initially done. These treatment are applied directly the scalp and hair. Specific application instructions vary. However, 8-12 hours after the initial application, the scalp should be re-examined for lice. If they are still very active, it may be necessary to treat again. Of note, you should NOT use conditioner prior to the treatment and then should not wash hair for 1-2 days after treatment is rinsed from hair.
Another option is to use Cetaphil gentle skin cleanser and a hair dryer. This treatment involves first using a fine-tooth lice comb to eliminate as many nits as possible. Then, you apply the Cetaphil to DRY hair, ensuring you coat each strand (it can be helpful to divide the hair into very small sections and apply to each individually). Once applied, use a regular comb to try and remove as much excess cleanser as possible. After this step is complete, use a hair dryer set on high to dry the Cetaphil. This may be time consuming, but it is necessary to ensure the cleanser is completely dry, as this forms a barrier that cuts off the oxygen to the lice. This should be left on for at least 8 hours. When the time is up, wash and dry hair normally and again use the lice comb. Repeat for a total of 3 times, one time per week. Between treatments, you should wash fabrics like bedding, pajamas that came into contact with the effected person and you should cleanse the combs by freezing.
If either of these treatments do not work, make an appointment with your doctor’s office to be seen.
Treatment should also be geared towards fabrics that may have come into contact with the infected person’s head for 2 days prior to diagnosis. (lice cannot live any longer than this when they are not on a person’s scalp) This includes vacuuming floors/rugs where the infected person’s head may have touched, washing the person’s clothing including hats, scarves, etc. in warm water. If there are items of concern that cannot be washed, sealing in a plastic bag for 2 weeks or placing in a freezer overnight will be enough to treat.
When reading about treatment, you may come across water-combing. While research studies results vary, it is likely effective in less than 50% of people. Therefore, water-combing is not recommended.
Prevention of head lice is first and foremost avoiding activities with head-to-head contact. Children do NOT need to be sent home early from school if head lice is identified. After the child has completed one treatment with either they permethrin or pyrethrin, they may return to school. This is often the next day. However, school systems may have different policies and may requiring the hair of the child to be free of nits and living lice prior to return.