Download - Head Lice
Presented by: LEE KIAN CHOY
IntroductionIt’s an ectoparasites that feeds on blood and sensitive
toward the light
Mostly occurs in school-aged (5-11 y.o) children (girls more prevalent than boys)
Infection are commonly characterized by pruritis caused by feaces antigen or lice’s saliva (weeks to develop)
Chronic scratching can lead to excoriation can lead to secondary bacterial infection
Nits are normally found in behind ears and neck
Life-Cycle of Head Lice:Able to live up to one month on human heads but can
only survive for up to 2 days away from humanAn adult female can produce an average of 56 eggs
once fertilizedEggs will hatched in 7-10 days of incubation (1cm
from scalp)Hatchlings will molts 3 times (9-12 days) to become
an adult
Mode of Transmission:Mostly by close contact as head lice are unable to
jump or fly, hence, they clawed/trapeze their way to others hair
Example of transmission route:a)Making social contacts (parent-child interaction)b)Shared combs, brushes, towels, clothing, beds and
closets
Note: Head to head contact is by far the most common route of transmission
Insecticide Treatment: Permethrin: causes electrochemical abnormalities across the
membranes of excitable cells, leading to sensory hyperexcitability, incoordination and collapse
Caution: hypersensitivity towards permethrin (chrysanthemums): if there is wound on the head: child < 2 y.o (safety has not been demostrated)
pregnancy (category B)
Direction to use: Wash the hair with normal shampoo rinse and towel dry until the hair is still slightly damp. Apply permethrin to the hair and scalp (avoid contact with eyes). Leave for ten minutes, then wash out thoroughly with water and towel dry. Use a fine toothed plastic comb to remove nits. One application is usually sufficient to kill those lice. To ensure complete eradication examine the scalp after seven to ten days and reapply to clear hatchlings
Insecticide Treatment:Pyrethrin: disrupt nerve impulse transmission in lice
resulting in paralysis and death (additional of piperonyl butoxide ONLY potentiate pyrethrin activity)
Caution: hypersensitivity towards permethrin (chrysanthemums): if there is wound on the head: child < 2 y.o (safety has not been demostrated)
pregnancy (category B)
Direction to use: Wash the hair with normal shampoo rinse and towel dry until the hair is still slightly damp. Apply pyrethrin to the hair and scalp (avoid contact with eyes). Leave for ten minutes, then wash out thoroughly with water and towel dry. Use a fine toothed plastic comb to remove nits. One application is usually sufficient to kill those lice. To ensure complete eradication examine the scalp after seven to ten days and reapply if necessary.
Insecticide Treatment:Malathion (lotion): Irreversible cholinesterase
inhibitor which is vital for nerve impulse transmission
Caution: contain flammable alcohol (avoid heat): not recommended for kids < 2 y.o: hypersensitivity towards insecticides
pregnancy (category C)
Direction to use: Apply lotion to dry hair & wash hair after 8-12 hours. Use fine-tooth comb to remove dead lice, repeat the procedure after 7 days
Insecticide Treatment:Benzyl alcohol 5% lotion: act by closing their
respiratory spiracles results in asphyxiation
Caution: if there is wound on the head: child less than 6 months old: hypersensitivity towards insecticides
pregnancy (category B)
Direction to use: Apply lotion to dry hair, using enough to completely saturate scalp and hair (avoid contact with eyes); rinse off with water after 10 min; repeat treatment in 1 wk
Insecticide Treatment:Gamma Benzene Hexachloride 0.1%: stimulates
nervous system of parasite, causing seizures and death
Caution: if there is wound on the head: not safe to be used in children: history of seizures
pregnancy (category C)
Direction to use: Apply to dry hair and surrounding areas (avoid contact with mouth or eyes); allow to set for 4 min, then lather for 4 min and rinse; repeat after 7 days when necessary
Manual Treatment:10 Day Hair Conditioner Treatmenta)Apply plenty of conditioner until saturated and comb
with normal hair comb to remove tangleb)Section the hair to four direction (forward, backward,
left & right) with fine-tooth nit comb (one section at a time)
c)Wipe the comb with tissue paper and look out for lice or nits (rinse hair after combing)
d)Repeats steps above every other day for 10 dayse)Check reinfestation once a week for four weeks after
the 10 days treatment
Practice Points:The following individual should NOT use insecticide
head lice treatment:a)Baby under 2 years of ageb)Patient with insecticide allergiesc)Scalp hypersensitivityd)Pregnant/breast feeding women
All insecticides does NOT 100% eradicate head lice eggs
Wet combing with vinegar can help in removing eggs that are attached to the hair
Note: Home remedy such as vaseline, mayonnaise & suffocation-based pediculicide lotion has been advocated but insufficient scientific research has been done
Self-Management:Check among family members to ensure others are not
affected & treat concurrently if affected
Comb and hair comb/brush should be treated concurrently with pediculicides or soak in hot water
Bedding should be laundered in hot water and dry clean
Isolate school-aged children from attending school until they are properly treated
Avoid over treating the head lice which can cause resistance
Note: Disinfecting the furniture is NOT necessary
Self-Management:Prevention:To avoid re-infection of head lice make sure affected
family members are treated
Comb the hair with hair gel or tie long hair together
Remind child of school age to avoid head to head contact
Shaving the hair can be considered as the most direct way of eradicating head lice (cosmetic unacceptable)
Thank You
Reference:http://www.public.health.wa.gov.au/cproot/473/2/Head%20Lice%20Fact%20Sheet.pdf
http://emedicine.medscape.com/article/785248-overview
http://pediatrics.about.com/cs/conditions/a/head_lice.htm
Australian Medicines Handbook (2007)