head lice

Pharmacy Practice IV

Prepared by Ibrahim Abdullah, BPharm (Hons) Nottingham, UK.

Head Lice // of 4

Head Lice (Singular = louse)

1. Pediculosis or Pediculus humanus capitis

2. Parasitic wingless insects found on the human heads:

a. Size 2 – 4mm, tan to greyish-white

b. Most commonly found on the scalp, behind the ears and near the neckline at the back of the neck

c. Hold on to hair with hook-like claws found at the end of each of their six legs

d. Rarely found on the body, eyelashes, or eyebrows

e. Feeds on extremely small amounts of blood drawn from the scalp.

f. Adult lice can live up to 30 days on a person's head. Off a person, it dies within 2 days

3. The eggs, called nits:

a. Very small, about the size of a knot in thread, hard to see

b. Like dandruff but cannot be flicked off, or hair spray droplets

c. Laid by the adult female at the base of the hair shaft nearest the scalp

d. Firmly attached to the hair shaft

e. Oval and usually yellow to white

f. Take about 1 week to hatch. Eggs that are likely to hatch are usually located within 1/4 inch of the

scalp

4. The nit hatches into a baby louse called a nymph. Nymphs mature into adults about

seven days after hatching

5. Very common infestation especially for kids ages 3 years to 12 years; girls more often

than boys

6. Head lice do not spread disease. Having head lice does not mean you are not clean

How Infestation Occurs

1. Directly

a. Lice can't fly or jump

b. Adapted claws that allow them to crawl and cling firmly to hair

c. Highly contagious

d. Especially prevalent if contact with an already infested especially in group settings – schools, child-

care centers sports activities, camps, and even playgrounds

2. Indirectly

a. Sharing clothing – hat scarves, coats

b. Sharing personal items - combs, brushes, or towels

c. Lying on a bed, couch, pillow, carpet, or stuffed animal that has recently been in contact with an

infested person

3. Head lice cannot live on pets, such as cats or dogs. Can’t pass to people vice versa



Head Lice // of 4

Diagnosis

1. Look for adult lice

a. Close to the scalp, behind the ears, the back of the neck

b. Few, small and move very fast. Visible but hard to find

2. Look for nits

a. Bigger, easier to see

b. Needs good lighting

c. But a child can have a few nits without actually having a case of head lice

d. Within a 1/4 inch of the scalp

e. If more than 1/4 inch from the scalp (and don't see a nymph or adult louse), the infestation is

probably an old one and does not need to be treated

3. Itching and scratching the head

a. Itching may not always start right away - depends on how sensitive skin is to the lice. It can

sometimes take weeks to start scratching

Symptoms

1. Tickling feeling of something moving in the hair

2. Itching, caused by an allergic reaction to the bites

3. Irritability

4. Sores on the head caused by scratching. Can sometimes become infected

Treatment - Medicines

1. Because lice are easily passed from person to person in the same house, other infested

family members will also need treatment to prevent the lice from coming back

2. Pesticides that kill lice, nymphs and maybe nits:

a. Permethrin. Quite safe to humans

b. Malathion

c. Lindane. Should not be used on infants or young children

3. Can be unsuccessful due to incorrect use or lice become resistant to the chemical in the

shampoo. Resistance to lindane, malathion and permethrin has been reported:

a. Don't use the same medication more than three times on one person

b. Don't use more than one head lice medication at a time

c. Don’t leave the shampoo or rinse in hair longer than directed

d. Rinse hair well after the treatment. Rinse over a sink, not in the bath or shower, so that other parts of

the body don’t come in contact with the product



Head Lice // of 4

e. Because eggs hatch 6 – 9 days after laying eggs, repeat the treatment in 7 to 10 days to make sure

all the nits have been killed

f. Do not use for kids two years old or younger

4. Use of dimeticone lotion:

a. Silicone-based lotion

b. After drying coats and smothers the lice causing its death either by suffocation or dehydration

c. Does not kill eggs, therefore the treatment should be repeated after 7-10 days

5. Use of Nuvo Method:

a. Uses the skin cleanser Cetaphil to suffocate the lice

b. Coating the scalp with the cleanser, removing the excess lotion from the hair with a comb, and using

a blow dryer to dry the lotion to the scalp

c. Dried coating must remain on the scalp for 8 hours and the course of treatment consists of three

applications done at one week intervals

Treatment – Nonpharmacological / Prevention

1. Home remedies like mayonnaise, petroleum jelly, olive oil or margarine. Make it hard for

lice to breathe, they probably won’t kill them

2. Natural products such as aniseed, coconut, neem and tea tree oils offer promise for new

compounds to treat head lice infestation. However, the number of clinical studies is very

limited

3. Since head lice don’t live long off the scalp you don’t need to do excessive cleaning. To

get rid of lice or nits from specific items, like hats or pillowcases, either one of these

methods will kill them:

a. Wash all bed linens and recently worn clothing in very hot water then put them in the hot cycle of the

dryer for at least 20 minutes

b. Dry clean any clothing that isn't machine washable, bed linens, clothing and stuffed animals

c. Put other things in airtight bags for two weeks

d. Vacuum carpets and any upholstered furniture

e. Soak hair-care items like combs, barrettes, hair ties or bands, headbands, and brushes in rubbing

alcohol or medicated shampoo for one hour. You can also wash them in hot water or just throw them

away

4. Manual removal using a fine-tooth comb on your child's hair after regular shampooing:

a. 30 – 40 minute daily for two weeks

b. Wet the hair to temporarily immobilizes the lice - easier to comb out

c. Space between the teeth of the comb should be no more than 0.3mm

d. Examination of the child’s head at regular intervals using a louse comb allows the diagnosis of louse

infestation at an early stage. Early diagnosis makes treatment easier and reduces the possibility of

infesting others. Additional examinations are necessary, if the child came in contact with infested

individuals, if the child frequently scratches his/her head, or if nits suddenly appear on the child’s hair



Head Lice // of 4

5. Shave the head or cutting the hair extremely. Not recommended for children due to the

psychological damage the child might experience

6. Keep long hair tidy

7. Educate:

a. Tell your child to try to, avoid head-to-head contact at school (in gym, on the playground, or during

sports) and while playing at home with other children

b. Tell your child not to share combs, brushes, hats, scarves, bandanas, ribbons, barrettes, hair ties or

bands, towels, helmets, or other personal care items with anyone else, whether they may have lice or

not

c. Tell your child not to lie on bedding pillows, and carpets that have recently been used by someone

with lice

8. Never use gasoline or kerosene. These products can be extremely dangerous

When to refer

Excessive scratching can also lead to a bacterial infection. This would require:

1. Antibiotic application – non-prescription

2. Oral antibiotic – prescription medicine

This article is for educational purpose only. The writer welcomes any feedback, which may be sent to

[email protected]

head lice

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