Millions of American children, particularly those in lower grades, become infested with head lice each year. Cleanliness is not the issue with this parasite bugs. Head lice have no preference for clean or dirty hair. Contagion from direct contact with infested pcrsons is the problem. Tenacious, blood sucking lice raise small red areas that itch severely and can lead to secondary infections.
While head lice or Pediculus humanus capitis compromise the most prominent insect species, two other types also infest humans. Pubic lice, Phthirus pubis, informally called “crabs,” are most frequently spread by sexual contact, bedding and shared linen. Body lice, or Oeducykys gynabys ciroirus sometimes disparaged as “cooties,” are uncommon in the U.S. but are capable of transmitting typhus epidemic relapsing fever.
Lice range in size from one to four millimeters long and are wingless with a flattened body. Their mouthparts are adapted for piercing and sucking. Their short legs have claws suitable for grasping and clinging to skin hairs and fibers. The tiny louse cannot jump, hop or fly, but can move relatively quickly.
The adult and the nymph stage of development immediately prior to adult are both blood sucking. They introduce saliva into their host during feeding. This causes a small reddened, raised and hard area (erythematous papule) that appears within a few hours.
When infestation initially occurs, it is generally mild, with 3 to 10 lice present. Each female will lay eggs (nits) at the rate of 3-10 per day and live 30-40 days. The lice are completely dependent on blood from their hosts and usually cannot survive away from hosts for more than 24 to 48 hours. The louse usually sucks blood for long periods of time, becomes engorged, and appears reddish in color.
Pediculosis is the infestation of blood sucking lice and is characterized by severe itching. Only humans transmit lice from one to another.
The symptoms are disturbing. The raised papule areas on the skin itch severely. With constant scratching, secondary bacterial infections may occur (such as impetigo or boils). Neither head lice nor pubic lice transmit infections directly, but severe scratching will. Dirt and bacteria under the fingernails transmit infections during scratching.
The first step to distinguish between head and pubic lice is the area of infestation. Head lice are usually found on the nape of the neck and behind the ears. Examination of these areas shows small, grayish-white eggs (nits). The nits may be mistaken for dandruff, but cannot be easily brushed away. Pubic lice are not always confined to the crotch or perianal area, but may attach to any hairy area of the body.
Head Lice – Millions of American children become infested with head lice each year, regardless of cleanliness. Head lice do not discriminate and can live in the scalp and hair of all children (and parents and other caregivers, should the infestation spread at home) regardless of sex, race, cleanliness or economic status. Lice are most often found on school-age children, particularly those in lower grades. Girls have higher incidence of lice than boys, while African-American children have a much lower incidence of infestation that Caucasian, Asian, or Hispanic children.
Infestation begins through direct, head-to-head contact with infested persons, by wearing infested clothing, using infested combs or hairbrushes, or lying on infested bedding, carpeting, or furniture. Some of the specific paths of contagion are children swapping hats or borrowing scarves; clothing hung close together in school coatrooms or using other’s combs or brushes. Other areas of transmission may be from bed linen, sleeping bags, headphones, and the headrests of chairs or couches.
The head louse is tiny, moves quickly through the hair and is difficult to see. A lice infestation is usually confirmed by finding nits, which are yellowish-white oval specks, attached to the hairs, generally near the scalp. In warmer climates, nits may be found several inches from the scalp.
Pubic Lice – Pubic lice are most frequently spread by sexual contact, by bedding and shared clothing and towels. Even toilet seats can spread pubic lice because the creatures can live 24-48 hours off the host.
Body Lice – Body lice are extremely rare in the U.S. and require medical supervision and diagnosis.
The head louse is a human parasite and cannot live on the body of a dog or cat.
Prevention – Caution children, particularly those in the lower elementary grades, against sharing playmates’ hats, other clothing or combs.
Suspecting an Infestation – Itching and scratching of the head is an important symptom. If that is happening, carefully check the head of the child or other family member for nits.
Treating People – In recent years, over the counter products including store brands in virtually all retail drug outlets are safe and effective treatments when used according to label instructions. These nonprescription products often include enzymes to loosen the “glue” that attaches nits or eggs to hair follicles, as well as lice killing active ingredients. Dispensed as liquid, lotion, gel or creme rinse, they are applied to the affected area for a few minutes and rinsed out. Fine tooth nit combs are then used to comb out any remaining nits or eggs.
When lice are discovered on one individual in a family, the other family members should also receive treatment, unless it is absolutely assured that they have not been exposed.
Persistent infestations may require retreatment at 1 – 2 week intervals. Some resistance to the commonly available treatments has been reported.
Treating the Home – Methods for controlling the spread of lice are tried and true. Washable items such as clothes, bed linens and towels should be washed in hot water, at least 130° F, and dried in a hot dryer for at least 20 minutes. Non-washable material items such as stuffed animals or pillows can be dry cleaned or stored in a tightly sealed plastic bag for at least 14 days. Personal items such as combs and brushes should be soaked in hot water. Be sure to vacuum carpets, chairs and couches thoroughly. It may be beneficial to use an over the counter or non prescription lice killing spray and then vacuum thoroughly.
The Community – Lice infestations are so common that no one should be embarrassed about discovering pediculosis. Notify school authorities about any infestation you observe, so other parents can be warned and a possible epidemic prevented. Inform your child’s playmates’ parents as well. It is important to protect all children as well as your own.