Head lice

Description

Head lice are small insects that feed on blood from the human scalp. Head lice most often affecting children. The insect is usually transmitted through direct transfer from the hair of one person to the hair of another.

Having head lice is not a sign of poor personal hygiene or an unclean living environment. Head lice do not carry bacterial or viral diseases.

Over the counter medications and prescription medications can help to treat head lice. Follow the treatment instructions carefully to remove the hair and scalp of the head lice and their eggs.

People also use a number of home or natural remedies to get rid of head lice. But there is little or no clinical evidence that they are effective.

Symptoms

The signs and symptoms of head lice may include:

  • The itching. The most common symptom of head lice is itching in the scalp, neck and ears. This is an allergic reaction to the bites of lice. When a person has head lice for the first time, the itching may not occur for 4 to 6 weeks.
  • Head lice on the scalp. You may be able to see the lice, but are often difficult to detect because they are small, avoid light, and move quickly.
  • Head lice eggs (nits) on hair shafts. Nits stick to the hair shafts and may be difficult to see because they are very small. They are the easiest to identify around the ears and the hairline of the nape of the neck. Empty nits may be easier to detect because they are lighter in colour, and away from the scalp. However, the presence of nits does not mean that there are live lice.
  • Sores on the scalp, neck and shoulders. The scratching can cause small red bumps that can sometimes become infected with bacteria.

When to see a doctor

See a health care provider before starting treatment if you suspect that you or your child have head lice. Your or your child's health care provider can confirm that head lice are present. Studies show that many children have received treatment for head lice with over the counter medications or home remedies when you do not have head lice.

Things that are often mistaken for nits are:

  • Dandruff
  • Waste products for hair
  • Hair ball dead tissue in a hair shaft
  • Scabs, dirt, or other debris
  • Other small insects found in the hair

Causes

A louse is a brown or grey insect the size of a strawberry seed. It feeds on human blood from the scalp. The female louse produces a sticky substance that adheres firmly to each egg to the base of a hair less than 1/4 inch (5 mm) in the scalp.

The louse life cycle

A louse passes through three stages:

  • The eggs hatch after 6 to 9 days.
  • The nymphs , immature forms of the lice, which become mature adults after 9 to 12 days.
  • Adult lice , which can live 3 to 4 weeks. The female head louse lays 6 to 10 eggs per day.

Transmission

Head lice crawl, but cannot jump or fly. Head lice are often spread from one person to another by direct contact of head-to-head contact, often within a family or among children who have close contact to school or play.

It is less common for head lice to spread without direct contact. But the insects can spread from one person to another through personal items, such as:

  • Hats and scarves
  • Brushes and combs
  • Hair accessories
  • Headphones
  • Pillows, towels and upholstery

Head lice can also spread when the elements of the clothing is stored together. For example, hats, or scarves hung on the same hook or stored in the same cabinet, the school could serve as vehicles for the spread of head lice.

Domestic animals, such as dogs and cats, do not play a role in the spread of head lice.

Risk factors

Head lice are spread mainly by direct head-to-head contact. So the risk of spread of head lice is higher among children who play or are going to school together. In the united States, the cases of head lice occur with greater frequency in children of preschool age to elementary school.

Complications

If your child scratches the itch on the scalp due to head lice, it is possible that the rupture of the skin and of developing an infection.

Prevention

It is difficult to prevent the spread of head lice among children in child care facilities and schools because there is not much contact.

The possibility of indirect spread of personal items is mild. However, to help prevent head lice from spreading, you can tell your child:

  • Hang clothes on a hanger, other children's clothing
  • Avoid sharing combs, brushes, hats and scarves
  • Avoid lying on beds, sofas, and pillows that have been in contact with a person who has head lice

It is not necessary to avoid the shared use of a helmet for sport and cycling to the time sharing is necessary to.

Head lice

Diagnosis

According to the American Academy of Pediatrics guidelines, the gold standard for the diagnosis of head lice is to identify a live nymph or adult louse.

The guidelines recommend that to examine the wet hair lubricated with hair conditioner or other product. Your child's health care provider will carefully comb your child's hair with a fine-toothed comb (nit comb) from the scalp to the end of the hair. If no live louse, the provider is likely repeat the entire exam at a second appointment.

The identification of nits

Your health care provider will also look for the nits in the hair of his son. To find nits, your child's provider may use a specialized light called a Wood's light, which makes the nits, to appear blue in color. But the identification of nits does not necessarily confirm the diagnosis of live lice.

Live nit needs to be close to the scalp to survive. Nits are more than 1/4 inch (6 millimeters) of the scalp is likely dead or empty. Suspect nits can be examined under a microscope to determine if they are living.

If the supplier does not find any live lice, are probably to the left of a previous case of head lice and need not be treated.

Treatment

Your doctor will probably recommend a medication available without a prescription that kills lice and some of the nits. These medications can not kill newly eggs. Therefore, a suitable time to second treatment is usually necessary to kill the nymphs after hatching, but before they become adult lice.

Some studies suggest that the re-treatment of 7 to 9 days after the first treatment is the ideal time for a second treatment, but other types of treatments that exist. Ask your health care provider for written instructions to a recommended treatment program.

Products sold without a prescription

Medications available without a prescription include:

  • Permethrin (Nix).Permethrin is a synthetic version of pyrethrin, which is a chemical compound extracted from the chrysanthemum flower. Permethrin is toxic to lice. Before using permethrin, wash your child's hair with shampoo but not conditioner. Rinsing your hair with white vinegar before washing hands can help dissolve the glue that holds the nits to the hair. Leave the medication on your hair by the amount of time indicated in the instructions on the package. Then rinse your child's hair over a sink with warm water. Permethrin does not kill the lice and nits, and the treatment must be repeated from 9 to 10 days after the first application. Side effects may include redness and itching of the scalp.
  • Ivermectin (Sklice). Ivermectin is toxic to lice. The lotion is approved for use in adults and children older than 6 months of age or older. Can be applied once your hair is dry and then rinse it off with water after 10 minutes.

Permethrin (Nix). Permethrin is a synthetic version of pyrethrin, which is a chemical compound extracted from the chrysanthemum flower. Permethrin is toxic to lice.

Before using permethrin, wash your child's hair with shampoo but not conditioner. Rinsing your hair with white vinegar before washing hands can help dissolve the glue that holds the nits to the hair. Leave the medication on your hair by the amount of time indicated in the instructions on the package. Then rinse your child's hair over a sink with warm water.

Permethrin does not kill the lice and nits, and the treatment must be repeated from 9 to 10 days after the first application. Side effects may include redness and itching of the scalp.

Prescription drugs

In some regions, the lice have developed resistance to the medications without prescription. Without a prescription treatment may also fail due to misuse, such as not to repeat the treatment at an appropriate time.

If the correct use over-the-counter treatment has failed, your doctor may recommend a treatment with a prescription. These include:

  • Spinosad (Natroba). Spinosad is approved for use in adults and children over 6 months of age and older. You can apply it to dry hair and rinse with warm water after 10 minutes. Kills the lice and the nits and generally does not need repeated treatment.
  • Malathion. Malathion is approved for use in adults and children 2 years of age or older. The lotion is applied, allowed to dry naturally and rinse after 8 to 12 hours. The drug has a high alcohol content, so that it can not be used with a hair dryer or near an open flame. Malathion can be applied 7 to 9 days after the first treatment if necessary.
  • Ivermectin (Stromectol). In addition to the recipe as a lotion, ivermectin is available by prescription in tablet form to take by mouth. Can be given to children who weigh more than 33 pounds, if other topical treatments do not eliminate the scalp of the head lice.

Self-care

If you prefer not to use a drug for the treatment of head lice, you may want to consider a treatment in the home. However, there is little or no clinical evidence that home treatments are effective.

Wet-hairstyle

Comb the wet hair with a fine-tooth comb, you can remove head lice and some nits. Studies show that the wet combing results will vary.

Start by wetting the hair and lubricants with hair conditioner or olive oil. Comb the entire head from the scalp to the end of the hair at least two times during a session. Normally, the process must be repeated every 3 to 4 days for several weeks — in less than two weeks after no more lice are found.

Essential oils

Small clinical studies have suggested that some natural plant oils can kill the lice by depriving them of air, but its effectiveness is uncertain. These products include:

  • Tea tree oil
  • Anise oil
  • Ylang-ylang oil

Essential oils are not required to comply with the safety, efficacy, and manufacturing standards used for drugs approved by the Food and Drug Administration (FDA), and can sometimes cause allergic reactions.

Choking agents

A number of household products used to treat head lice. These products are intended to deprive the lice of air when generous amounts apply to the hair, covered with a shower cap, and to the left in the night. The products used for this purpose are:

  • Mayonnaise
  • Olive oil
  • Margarine or butter
  • Petroleum jelly

However, it is not clear whether these treatments are effective.

Dehydration

Another option is a machine that uses an application of hot air to kill lice and eggs through dehydration. The machine requires special training and is currently only available in the professional head lice treatment centers.

The machine uses air that is colder than most hair dryers, and a higher flow rate to kill the lice to dry. No regular use of a hair dryer to achieve this result, since it is too hot and can burn the scalp.

Dangerous products to avoid

Flammable products, such as kerosene or gasoline must never be used to kill head lice or to remove the nits.

Home cleaning

Head lice usually do not live more than a day without eating from the human scalp. And the eggs cannot survive without the temperature near the scalp. Therefore, the possibility that lice can survive on items for the home is small.

As a precautionary measure, you can clean items that the person affected has been used in the previous two days. The cleaning of the recommendations are the following:

  • Wash items in hot water. Wash bedding, stuffed animals and clothing in hot, soapy water — at least 130 ° f (54.4 ° c) and dry at high temperatures.
  • The hair clean and care items. Clean combs, brushes and hair accessories by soaking in hot, soapy water for 5 to 10 minutes.
  • Seal items in plastic bags. Seal of items that cannot be washed in plastic bags for two weeks.
  • Vacuum. Give your floor and furniture upholstery, a good vacuuming.

Preparing for your appointment

See your family's health care provider or pediatrician if you suspect your child has head lice. The doctor will examine the child's scalp and look for a live nymph or adult louse to determine if he or she has head lice. The provider can carefully inspect your child's hair. If necessary, the doctor will examine the suspected items under a microscope before confirming that the lice are present.

The symptoms and treatment of Head lice