Help Patients Get Rid of Head Lice

Head lice are small, wingless insects that feed on human blood, while head lice infestation usually affects children and transfers from the head of 1 person to another.

Scientists think that human head lice were first transferred to humans from chimpanzees about 5.5 million years ago. Researchers think that human lice developed into 2 distinct types: body and head lice around 100,000 BC.¹ Egyptian mummies, dated from 3000 BC, were found with nits, or lice eggs, preserved on their heads. There are 3 types of lice that can live on humans: body lice (Pediculus humanus corporis), head lice (Pediculus humanus capitis), and pubic lice (Phthirus pubis). Of these, only body lice are known to spread disease. However, head lice are the most common form of lice infestation.² An estimated 6 million to 12 million infestations of head lice occur each year in the United States among children between the ages of 3 and 11 years.³

Head lice infestations occur mainly on the scalp but can also be found on the eyebrows or eyelashes. A common misconception about head lice infestation is its association with environmental cleanliness and personal hygiene. However, these factors are not associated with having or transmitting the parasite. Head lice is usually spread through direct head-to-head contact with an infected person, as the lice can only move by crawling rather than by flying or jumping. As a result, outbreaks are common in places, such as daycare centers, elementary schools, and homes, where such contact is likely to occur.

Because head lice do not transmit a symptomatic disease, they are not considered a health hazard. The infestation can be asymptomatic. However, most individuals experience common symptoms of a sensation of something moving in the hair or a tickling feeling, followed by itching that is caused by an allergic reaction to lice bites. Excessive scratching from these symptoms can lead to a secondary bacterial infection. Therefore, it is best to detect and treat infestations early.²

Diagnosis is established by detection with the naked eye of adult or baby lice or nits, according to the American Academy of Pediatrics (AAP).

Common areas to focus on during inspection include the base of the neck, behind the ears, and the crown of the head. This process may be aided by using a lice or nit comb, along with lubricants to minimize static electricity and slow lice movement.

Once an infestation is established, a combination of nonpharmacologic and pharmacologic interventions are required, as none of the pediculicides are 100% ovicidal. As a result, the National Pediculosis Association recommends physical removal of the nits using an FDA-approved nit comb. Guidelines established by the AAP recommend using 1% permethrin or pyrethrins, both available over the counter, as first-line agents. However, if resistance to permethrin or pyrethrins has been reported in the region, patients should be referred to a health care provider for 1 of the following prescription medications approved by the FDA for head lice: 1% benzyl alcohol lotion (2009), 0.5% ivermectin lotion (2012), 0.5% malathion lotion (1989), or 0.9% Spinosad topical suspension (2011). Other treatment options used as second-line agents include 1% Lindane shampoo.³

When treating head lice, recommendations are not to use more than the directed amount of lice medication unless instructed by the provider. Avoid medication contact with the eyes, and do not treat the affected person more than 2 to 3 times with the same medication if it does not seem to be working. Additionally, providers recommend not to use multiple treatment options at the same time. Finally, patients should rinse these topical pediculicides from the hair, over the sink, rather than in the shower, to minimize skin exposure, and use warm rather than hot water to minimize absorption.³

Home remedies for lice treatment may include wet combing, to remove active lice and nits. Essential oils, such as plant and tea tree oils, are often used to suffocate lice, while agents such as olive oil and petroleum jelly are thought to smother lice if left in the hair overnight. However, the effectiveness of these treatments is unclear.⁴

Recently, the FDA approved the transition of Ivermectin 0.5% lotion from a prescription-only product to an OTC treatment, as it was proven effective and safe for general use. This switch will allow consumers to have increased access to the medication. ⁵

With more OTC options available, more patients suffering from head lice can be treated in a timely fashion. By reducing the need to be seen by a provider first, patients can treat infestations earlier, increasing the chance of treatment success.

Saro Arakelians, PharmD, is vice president of pharmacy operations at Mini Pharmacy in Los Angeles, California. Ngoctran Tran is a PharmD candidate at the University of Southern California School of Pharmacy in Los Angeles.

REFERENCES

• A brief look at the history of headlice. Lice Clinics USA. November 22, 2017. Accessed November 11, 2020. https://lcastcharles.com/brief-look-history-headlice/#:~:text=Roughly%20100%2C000%20BC%20scientists%20believe,head%20lice%20and%20body%20lice.&text=Egyptians%20mummies%20and%20archaeological%20findings,were%20literally%20crawling%20with%20lice
• Devore CD, Schutze GE, AAP, Council on School Health, Committee on Infectious Diseases. Head lice. Pediatrics. 2015;136(4):781-782. doi:10.1542/peds.2015-2696
• CDC. Parasites - lice. September 11, 2019. Accessed November 11, 2020. https://www.cdc.gov/parasites/lice/index.html
• Mayo Clinic. Head lice. Accessed November 11, 2020. https://www.mayoclinic.org/diseases-conditions/head-lice/diagnosis-treatment/drc-20356186?fbclid=IwAR1dGlcaxS2Mh1sMsRS5kJNJ2ZAnovJp_JWEMUmzV6Qh9rA4Er-l5JDWijU
• FDA. FDA approves lotion for nonprescription use to treat head lice. October 27, 2020. Accessed November 11, 2020. https://www.fda.gov/news-events/press-announcements/fda-approves-lotion-nonprescription-use-treat-head-lice