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Head Lice (Pediculosis Capitis)

Head lice is a common condition that affects children most frequently. It can be traumatic for both children and parents.

Life Cycle of Head Lice

-  Female louse lives for 1 month and can lay up to 10 eggs per day!

-  Eggs (nits) take 8 days to hatch. Eggs release nymphs that mature in 8 days.

-  Adult head lice are gray-white and 2-3 mm in length o Theyfeedonthescalp, face, and neck.
- They can live up to 55 hours without a host!

How do head lice get “spread”?

-  Through direct contact with the head of an infested person

-  Lice do not jump, fly, or use pets as vectors!

-  Spread via inanimate objects is controversial

Signs & Symptoms

-  Itching around scalp, neck, and ears due to an allergic reaction to lice saliva

-  Visible lice and nits

How can my child be diagnosed with head lice?

-  Confirmed by visualization of live lice (Nits are white and more visible than nymphs and adult lice)

-  This may be done through wet or dry combing

How do I wet comb my child’s hair?

-  Apply hair conditioner to hair

-  Brush/comb hair to remove tangles

-  Fine-toothed comb is inserted near crown so that it gently touches the scalp

-  Draw comb down firmly

-  Examine for lice after each stroke

-  Comb entire head twice

Treatment is recommended!

Topical pediculicides may be prescribed for your child:

-  Pyrethroids

-  Malathion

-  Benzyl alcohol

-  Spinosad

-  Topical ivermectin
Wet combing may be used in young infants and in patients who wish to avoid medications

-  Session is complete when no more lice are found.

-  Repeat sessions every 3-4 days for several weeks.

-  Continue for 2 weeks after any session a large, adult louse is found.

Which topical medication is right for my child?

Your child’s pediatrician will make a decision based on: o Resistancetomedications
o Side effects
o Patient age

o Drug cost

How to apply topical medications:

-  Hair conditioners should not be applied prior to application!

-  Limit skin exposure:

- Rinse topical pediculicide off over a sink rather than a shower or bath

-  Rinse with warm water instead of hot water

“My child has used 2 topical medications and still has lice!”

-  Some causes of treatment failure are:

-  lack of adherence to treatment

-  continue contact with other infested individuals

-  resistance to specific topical treatments
If 2 topical medications fail, your child may be prescribed an oral medication called Ivermectin

When can my child return to school?

According to the CDC:
- Children should not be excluded from school based upon presence of live lice/nits
- Affected children should avoid direct head contact with other individuals and should be treated promptly

Household Recommendations:

-  Examine household members → treat if infested

-  Bedmates should be treated prophylactically

-  Recommend washing clothing and linen used by infested person in hot water and drying items in

high-heat dryer cycle

-  Alternative: dry-cleaning; storing in a sealed plastic bag for 2 weeks

-  Vacuum furniture & carpeting (but risk of transmission is low here!)


Goldstein, A. and Goldstein, B. (2019). UpToDate. [online] Available at: [Accessed 10 Dec. 2019].

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