Head Lice

Question 1

Why does the scalp itch in pts with head lice?

Answer 1

the itching is caused due to an allergic response of the scalp to the saliva of the live and can take weeks to develop

Question 2

What questions would you ask a pt who thinks they have head lice?

Answer 2

Have live live been seen? - check both wet and dry combing

Have you seen empty egg shells (nits)? - egg shells does not constitute evidence of current infestation and are not removed by insecticides

any itching? - not always present - check signs of dandruff, psoriasis or seborrhoeic dematitis

Question 3

What is dry combing?

Answer 3

Dry comb your hair with a normal comb
once the hair moves freely - switch to detection comb - starting from the back of the head comb from the scalp down to the end of the hair

Question 4

What is wet combing?

Answer 4

wash hair with normal shampoo 
apply hair conditioner 
repeat steps 1-4 as for dry combing
rinse out the conditioner 
should be performed on all family members

Question 5

what are conditions to eliminate?

Answer 5

Dandruff - irritation and itching of the scalp
Seborrhoeic dermatitis - affects scalp and face. in infants the child will have large yellow scales and crusts of the scalp

Question 6

What tx options are available for head lice?

Answer 6

1. Insecticides - Malathion - most effective, permethrin
2. Dimeticone
3. Isopropyl myristate
4. Head lice should be treated with lotions, creams or liquid rinse formulations
5. Alcohol formulations have been effective in asthmatic pts and pts with severe eczema where aqs formulations are safer

Question 7

How does dimeticone work?

Answer 7

Coats the lice both internally and externally which leads to disruption in water excretion causing the gut of the lice to rupture from osmotic stress

Question 8

How does isopropyl myristate work?

Answer 8

blocking the tracheal breathing system and coating the surface of the live with a thin film of fluid

Question 9

Should tx be repeated?

Answer 9

Yes.

Question 10

When should insecticides be repeated and for how long?

Answer 10

Re-applied after 7 days to tx any lice that had not been hatched by the time of the first application

Question 11

How long should you do wet combing for?

Answer 11

Every four days for at least 2 weeks

Question 12

Which products cannot be sold for a child at 6 months?

Answer 12

Isopropyl myristate

Question 13

What age can Malathion and dimeticone be sold?

Answer 13

> 6 months

Question 14

Can all treatment options be used for women who are BF or pregnant?

Answer 14

Yes

Question 15

How would you know if tx has failed?

Answer 15

Wet combing: is performed for after any tx to confirm head lice eradication for 3 consecutive sessions

insecticides + the others: 2-3 days after try wet combing completing tx. repeat after 8-10 days after tx if no lice are found

Question 16

How would you use malathion?

Answer 16

Derbac M (malathion) should be applied to dry hair and left for 12 hours before washing off

Question 17

How is dimeticone lotion&Spray used?

Answer 17

Hedrin (dimeticone) is applied to dry hair ensuring that it is spread evenly from the hair root to the tips. should be left on for 8 hours

Question 18

How should dimeticone gel be applied?

Answer 18

same as the lotion but leave on the hair for 15 minutes

Question 19

How should dimeticone spray be used for?

Answer 19

comb with fine-toothed comb before applying the spray over the entire head - leave on the head for 30 minutes before re-combing the hair
should only be used for pts over 2 years

Question 20

Can anything be used prophylactically?

Answer 20

Nothing.

insecticides should NOT be used for prophylaxis as this accelerates resistance

Question 21

Should all household members be treated?

Answer 21

only treat those who are affected

Question 22

Can products stain clothes?

Answer 22

products can stain clothing, bedding, pillows cases etc and can also have a strong smell