Randy Jacobs, M.D. Patient Education

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Lice Head and Pubic


What is a head louse? The head louse is one variety of a number of different lice. This type has chosen to make your scalp, and the hair on it, its home. Head lice complete their life cycle on your scalp in approximately one month and new generations multiply rapidly, over and over again. The same principles apply to pubic lice, however, pubic lice are primarily sexually transmitted while head lice are not necessarily transmitted sexually.


How do they live? During all stages of their life cycle, lice need to feed frequently on human blood. The optimum temperature for head lice is about 85^F. When the temperature of their environment rises of falls, such as a person with a high fever, or a dead person, the lice will leave to seek a new host. The adult female head louse lays eggs (nits) which she glues to the hair shaft with a tenacious material applied near the root of the hair. The young lice hatch approximately 10 days later and emerge as miniature replicas of the adults. In order to survive, the newborn fouse must feed within 24 hours. Under favorable conditions, the head louse will reach maturity in about two weeks. During its 20 to 30 days of life, the female louse can deposit as many as six eggs per day, so there may be hundreds of nits in a single manifestation.


How do you get them? Head or pubic lice are usually transmitted from one infested person to another by direct contact with the hair either scalp or pubic. Pubic lice are primarily sexually transmitted. Personal items like combs, brushes, towels and bedding are other frequent sources of contamination. Another common source of infestation is clothing, such as hats, ribbons, scarves, topcoats and sweaters, all of which provide excellent transportation from one individual to another. Head lice do not observe any class distinction; they can infest anyone and are a problem which is rapidly gaining ground in all strata of our society. The schoolgirl who borrows a comb, the student trying on a hat in an East Village shop, children who share a bed in a crowded home, the traveler resting his head against the back of an airline seat can each fall victim to a head louse infestation.


What does a head  or pubic louse look like? Head lice are insects, flattened in shape from top to bottom, they have no wings and do not jump or fly. Their mouths include a set of six pairs of hooks by which they can attach themselves to the hair shaft. They possess short, stout legs equipped with large claws for grasping and holding onto human hair. While they look terrifying when magnified, they actually measure only approximately one-tenth to one-eight of an inch in length. Shown here is a picture of a head louse (magnified) and a picture of a nit attached to a pubic or scalp hair shaft.


How do you know if you have head  or pubic lice? Although the lice are difficult to see, they are easy to recognize, provided you are actually looking for them. One telltale sign is a persistent itch of the scalp, often accompanied by infected scratch marks or what appears to be a rash. Closer inspection, possibly aided by a hand lens, will reveal small, silvery eggs attached to individual hairs . In checking the scalp, pay particular attention to the back of the head and the area behind the ears; lice live mainly in the area at the back of the head, although they will occasionally migrate to the beard or eyebrows. In severe cases of infestation, occasionally swollen lymph glands are noted in the neck or under the arms or in the groin.


How do you treat head or pubic louse infestation? It is usually best to seek medical help for diagnosis and advice on treatment. While there are remedies that can be purchased in drug stores, your doctor will prescribe a more effective, specific medication after a definite diagnosis has been established. The most modern prescription remedy is an easy-to-use shampoo which does not require shaving the head, has no telltale odor and usually eliminates the problem with one application. Following your doctor's recommendations, about two tablespoonful of the shampoo should be poured onto the affected hairy area. The scalp or pubic hair should be thoroughly wetted with warm water and worked into a good lather. Shampoo vigorously for at least four minutes, as you would with any other shampoo, being sure to cover all hairy areas. Rinse the hair thoroughly and rub dry with a clean towel. The prescription shampoo kills the unborn lice in the eggs. However, removal of the eggs is often difficult because of the tough cement which attaches them to the hair shaft. Thorough combing and brushing with a clean brush is often necessary, in stubborn cases, a fine-tooth comb should be used. All personal items, such as combs, brushes, hats and clothing, should be either boiled or dry-cleaned. Lice and their nits can survive (for a time) off the human host. Thus, even though you may have been successful in eliminating your infestation, immediate reinfestation is possible or a fresh infestation of other family members may occur. R & C Spray insecticide should be sprayed on upholstery, blankets, bedding, and other objects where lice and their eggs are known to linger, to help break the infestation and reinfestation cycle. R & C Spray is available at your pharmacy. If one person in a family, camp, school, or other institution has had lice, there is a strong possibility that others will too. Therefore, everyone should be checked and the recommended treatment applied to all persons who may have been infested. Remember, head or pubic lice can happen to anyone, clean or dirty, rich or poor. The most important fact to remember is that the problem should be quickly treated because delays will only help to spread the infestation throughout the community.