Treatment of head lice

Head lice infestation may be treated by medicated shampoos and physical removal of the lice.

Outline of medical management includes medications, combing, and so forth. (1 – 6)


Lotions and shampoos with 1% Permethrin or 1% Lidane. These are available over-the-counter without a prescription.

Instructions on the bottle should be followed closely. In case of long hair more quantities of the lotion may be needed. The lotion may be needed to be kept on for 12 hours or more.

Malathion 0.5% in isopropanol is also approved for the treatment of head lice. It is applied to dry hair until the hair and scalp are wet. Then the medication is left on for 12 hours.

Malathion works in resistant cases of head lice. It has certain significant side effects in children younger than 6 months old and the elderly.

Repeated application and application in these extremes of ages is avoided.

Another new drug is approved for head lice removal by the US Food and Drug Administration (FDA) in 2011. It can be used in patients aged 4 years and older.

The cream is available as cream rinse to be left on dry hair for 10 minutes, and then shampooed out. This drug kills the nits and requires no follow up with combing to remove the eggs.

Side effects of medications

Children below 2 years may develop side effects to the anti-louse medications. The Centers for Disease Prevention and Control advises that in this age group of children treatment should be manual removal of nits and lice.


Nits can be removed using a nit comb. Olive oil is rubbed over the hair before attempting to remove the nits.

The comb may also be run through beeswax. This helps make the nits easier to remove.

Nits need to be removed and then combing is repeated in 7 – 10 days.

Combing may be of two types – Wet and Dry.

The comb usually has 0.3mm space between the teeth to trap the smallest lice and nymph.

For wet combing the hair may be washed with an ordinary shampoo and conditioner. A normal comb is used to untangle the hair.

This is followed by a fine toothed comb to remove the nits and lice. The comb is used systematically all over the head with particular attention to the base of the hair.

How do you know if treatment is working?

The CDC says that if after 8-12 hours after medical therapy the lice slow in movements or are dead then the treatment is working.

Usually it takes 2 to 3 days of treatment before hair is washed.

Treatment should be repeated in 7 to 10 days time to kill the newly hatched lice.

Itching may last for 7 to 10 days after successful therapy and does not mean that the therapy is not working.

Washing of clothes and bed linens

All clothes and bed linens should be washed in hot water (at least 130°F) with detergent. This helps to prevent head lice from spreading to others.

Floor, carpets and surfaces that the infected person sat on also need to be vacuumed.

Items that are nonwashable which have come in contact with a person infested with head lice should be wrapped in plastic bags for 2 weeks. This will kills any surviving eggs.

Hair combs and brushes should be disinfected in hot water (at least 130°F) or alcohol by soaking for 5 to 10 minutes or more.

All household members with head lice infestation should be treated simultaneously to prevent recurrent infections.

Oral drugs

For severe infections oral medications may be prescribed.

Ivermectin is sometimes prescribed for severe head lice especially in the severely ill or immunosuppressed patients.

Some patients also show benefits if Ivermectin solution is applied locally over infested areas.

Prevention of head lice

Prevention of head lice includes (1, 2):

  • Combs, hair brushes, hats, scarves, bedding, clothing, helmets, head phones and towels should not be shared with individuals with head lice.
  • Children with head lice are often not allowed to school, day-care centers, preschools, and nurseries unless the infestation is removed to prevent spread.



Further Reading

  • All Head Lice Content
  • What is head lice?
  • Head lice Causes
  • Head lice Symptoms
  • Head lice Diagnosis

Last Updated: Jun 5, 2019

Written by

Dr. Ananya Mandal

Dr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well.

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