Challenges of a False Negative Head Lice Screening


Head lice is spread through head-to-head contact. When one family member has lice, it is highly likely others in the family have it as well.

We are often told by people that we are head screening or treating that other family members do not have lice because (fill in the blank: they/mom/dad/mother-in-law/friend/doctor/cosmetologist) screened them and found nothing only for them to find out later than the other family member did in fact have head lice.

Risks to a patient of a false negative head screen include: delayed or lack of supportive treatment, lack of monitoring of infected individuals and their household or other close contacts for symptoms resulting in increase risk of spread of head lice within the household and community, reinfestation of the person we treated.

As a result, for our customer’s protection we require our certified head lice technicians to head screen all immediate family members within 24 hours of treatment if you would like to qualify for our optional 30-day lice free guarantee.

If you are experiencing any head lice symptoms or have been recently exposed to others that you know have head lice, we recommend a thorough head screen to reduce the risk of a false negative head screen.

A proper lice head screening includes:

  1. Dry hair for the person getting screened
  2. Detangled hair of the person getting screened
  3. Proper lighting
  4. Proper height distance of person being screened from the person performing the inspection
  5. A hair strand by hair strand inspection to find any lice eggs glued to the hair
  6. Use of a professional, stainless-steel lice comb to perform the inspection
  7. Good eye site from the person doing the head inspection
  8. Patience and time from both people.  The person getting screened needs to sit still and the person doing the head screen needs to have steady hands going through the hair strand-by-strand.  Depending on length of hair, a proper, thorough head screen will take about 15 minutes but can be as quick as 5 minutes for short hair and as long as 30 minutes for long hair.   

In conclusion, lice eggs are the size of a grain of sand, glued to the hair strand, and do not move. You are truly looking for a needle in a haystack. Also, only 40% of people that have lice exhibit any symptoms of head lice such as each and so it is very easy for a person to arrive at the conclusion the person they are screening is lice free even though they have an active head lice infestation.  The false negative head screen can lead to head lice infestations for many others and create a whole lot more stress that could have been avoided by conducting a proper head screen.

Torrance Lice Removal has been in business since 2015 and has successfully head screened and treated over 40,000 families from all over Southern California at our professional head lice clinic. We charge $25 for a professional head screen and $20 to screen an immediate family member of a person that we are treating for lice. The head screen charge is waived if treatment is provide.