HEAD LICE: Nit tips

With recent outbreaks abound and the fear of a household outbreak even greater, it warrants that we touch on the subject of head lice. Also known as pediculosis capitus, this aggravating insect affects a greater number of elementary students on this continent than all other communicable diseases combined, with the exception of the common cold. (1)

Although it is not clear exactly how head lice are transmitted, it is presumed to be related to communal combs, towels, hats, bedding, floors, and others. Lice do not fly or jump and they do not use pets a vectors for transmission. Head lice also do not carry disease.

A common myth is that only unhygienic people get head lice. In fact, hygiene and household cleanliness are not factors in infestation.

Prohibitive to the identification and treatment of the infestation is the fact that most people with it don't have symptoms. Interestingly, some children can carry a large colony of these lice without any complaint. Others note itching of the scalp and affected areas, which can also include the ears and neck, from the louse saliva which is excreted when it feeds. Lice survive by feeding on human blood.

Head lice are three to four millimeters in length and both male and female counterparts are equipped with the mouth parts with which to feed and legs to grasp the hair. The female louse lives about a month. She lays eggs daily, the commonly referred to "nits" that look like white capsules that adhere to the base of the hair.

Similar as the hunt for ticks, it helps when looking for head lice systematically using a fine-toothed comb (with teeth 0.2 mm apart). When looking, it is helpful to have the hair wet with water or conditioner. Finding nits does not necessarily imply there is an active infestation, as the nits may persist for months after treatment.

Topical insecticides, mostly, permethrin (brand names Nix and Elimite) are most commonly used to eradicate the lice. These lice treatments are available over the counter and often come in a package that includes a fine-toothed comb.

The permethrin is applied via a lotion to the scalp. It is not as effective if hair conditioner is in the hair prior to treatment. (2) Most common side effects of treatment include burning, itching, and redness of the area. Permethrin is not recommended for children under the age of two months.

Wet combing can also be helpful in treating and eradicating a case of head lice, but must be done repeatedly every few days for several weeks, until no more nits or lice are found. Using water or conditioner to the hair and a fine-toothed comb, a wet combing session should last up to 30 minutes, or longer for longer, thicker hair.

Home remedies such as oil, butter, or petroleum jelly have been suggested but have been found ineffective in adequately killing the lice.

Each member of the household should be examined for lice and treated if infested. (3) Bedmates should be treated even no evidence of head lice were found on the scalp.

It is not likely that a louse will survive off a scalp for more than 48 hours. Because of this, it is advisable to wash clothing and linen used by the infested person during the two days before therapy. Hot water and drying in the high-heat cycle is most effective. (4) Non washable items may be dry cleaned or stored in a sealed plastic bag for two weeks. (3) Vacuuming the affected furniture and carpet is also often suggested. (5)

Spraying the house with a fumigant is generally not recommended as it can be toxic. (6)

Head lice are most commonly spread by direct head-to-head or hair-to-hair contact. The risk of getting infested by sharing clothing or sitting on the same carpet as someone who is harboring the insect is actually small. This is because lice do not jump or fly, and cannot survive more than one to two days without feeding. Further, the nits usually die if not kept the same temperature as the scalp. (7)

That being said, it is advisable to avoid sharing potential items that may spread the lice, such as brushes, hats and clothing.

To help control a head lice outbreak in a school, camp, or community, we can teach our children to avoid activities that may spread this very irritating insect.

REFERENCES:
1. Ko CJ, Elston DM. Pediculosis. J Am Acad DErmatol 2004; 50:1.
2. Lebwohl M, Clark L, Levitt J. Therapy for head lice based on life cycle, resistance, and safety considerations. Pediatrics 2007; 119:965.
3. Devore CD, Schutze GE. Council on School Health and Committee on Infectious Diseases, American Academy of Pediatrics. Head lice. Pediatrics 2015; 135:e1355.
4. Frankowski BL, Weiner LB. Committee on School Health the Committee on Infectious Diseases. American Academy of Pediatrics. Head lice. Pediatrics 002; 110:638.
5. Head lice. Centers for Disease Control and Prevention. www.cdc.gov/lice/head/index.html. (Accessed on 20 August 2015).
6. Head lice. Centers for Disease Control and Prevention. www.cdc.gov/parasites/lice/heat/treatment.html. (Accessed on 20 August 2015).
7. Head lice. Centers for Disease Control and Prevention. www.cdc.gov/parasites/lice/head/prevent.html. (Accessed on 20 August 2015).

Michele Brannan is a certified Physician Assistant of Internal Medicine and has been in practice in the Riverbend area for over 10 years.
The health information provided herein is not intended to replace the advice or discussion with a healthcare provider and is for educational purposes only. Before making any decisions regarding your health, speak with your healthcare provider.

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