Lice is the common name for an infestation of the hair and scalp caused by exposure to a specific insect.  Lice are small gray bugs that lay eggs in the hair, which leads to scalp itchiness and sometimes a rash. They can be treated at home with the proper products and technique.  There are no lasting problems following a lice infestation, and aside from scalp itching children often feel well.

Signs and symptoms

Lice are 2mm long gray insects.  Nits are white eggs firmly attached to hair near the scalp that cannot be removed by gentle scratching.  Nits are most commonly found in the dark areas of the scalp, such as behind the ears, at the base of the neck, and along the central scalp.  Scalp itchiness is the primary symptom of lice. 


Diagnosis of lice requires direct visualization.  Nits are often easier to identify than lice, because they are more numerous and white in color.   However, the presence of nits alone does not diagnose an active lice infection, as they can be killed with proper treatment but can only be removed manually.


Proper lice treatment requires killing all active insects and nits.  It is critical to follow the instructions for lice treatment exactly to ensure proper treatment and reduce the risk of recurrence. 

Permethrin (Nix)

  1. Wash the hair with shampoo only and towel dry.DO NOT USE CONDITIONER as it interferes with proper treatment
  2. Pour the full 2oz bottle of nix into damp hair.If your child’s hair is long, it may take more than 1 full bottle to coat the hair from the scalp to the ends
  3. Massage the cream into the hair to ensure all the hair is coated with Nix
  4. Leave Nix in the hair for a full 10 minutes
  5. Rinse the hair with water and towel dry again
  6. Repeat treatment in 9 days

If Nix is used properly there is no need to remove all nits.  Only active lice can transmit lice.  However, some schools have a no-nit policy that requires the removal of all nits prior to return.  Nits can be removed by using a special nit comb.  Nit combs are most effective if done on very small segments of wet hair.

After treatment, hair should NOT be washed for 2 days.  Conditioner should be avoided for 2 weeks.  If Nix fails, cetaphil cleanser can be used as a second line treatment option.

Cetaphil/Nuvo method

  1. Apply Cetaphil Gentle Skin Cleanser to dry hair, coating the head from scalp to hair tips
  2. Wait 2 minutes
  3. Comb out excess Cetaphil and visible nits
  4. Blow dry your child’s hair thoroughly
  5. Leave the dry Cetaphil on the hair for at least 8 hours
  6. Wash the hair with a regular shampoo
  7. Repeat this process twice at 1 week intervals


Transmission of lice occurs by direct contact.  Lice cannot jump or fly. Nits cannot transmit lice, and lice can only survive for up to 24 hours when not on the body.  The best way to prevent lice is to limit hair-to-hair contact.  That means limiting the sharing of pillows, brushes, combs, hats and other items that come in direct contact with the head. 

If one child in the home has lice, all other members of the house should be checked.  Cleaning the household after lice involves vacuuming the bedroom, washing all sheets and bedding in hot water and soaking all hair brushes in the proper solution.  If this cannot be done, placing possible contaminated items in a sealed bag for 2 weeks suffocates the lice. 

Takeaway message

Lice is a scalp infestation that is itchy but not harmful.  Only active lice can transmit lice.  Proper treatment of lice and the environment is important for full treatment. 

Additional Information

Information of lice treatment and on common myths and facts about lice from the American Academy of Pediatrics.