Head Lice

1
Head Lice

• Lawrence Pike

2
Introduction

• Head lice are one of the most common human
  ectoparasites
• They do not carry serious diseases
• In many cases they do not cause symptoms

3
Symptoms

• Many patients are asymptomatic, the lice and nits
  only being detected by careful examination of the
  scalp.
• Pruritus is a common symptom. Excoriations may
  lead to impetigo and furunculosis.
• Head lice infestation usually starts above the
  ears and around the hair line. They are rarely
  found in eyelashes or eyebrows.
• The live lice and nits are usually visible to the
  naked eye, but a magnifying glass may help.
• The duration of infestation may be estimated by
  the distance from the scalp surface to the nit on
  the hair shaft (the hair grows about 5mm per
  week).

4
Signs

• Head lice infestation usually starts above the
  ears and around the hair line. They are rarely
  found in eyelashes or eyebrows.
• The live lice and nits are usually visible to the
  naked eye, but a magnifying glass may help.
• The duration of infestation may be estimated by
  the distance from the scalp surface to the nit on
  the hair shaft (the hair grows about 5mm per
  week)

5
Causes

• Social status means nothing to lice. They are
  common amongst children and infection has nothing
  to do with dirty living. Head lice cannot fly,
  jump or swim but are spread by clambering from
  head to head. Anyone with hair can catch them.

6
Detection

• Head lice are well camouflaged and hide when
  disturbed by combing. If few in number they can
  be difficult to detect.
• To check for lice, comb the hair regularly while
  wet with a fine-tooth comb. Use a conditioner
  to make combing easier.

7
Self Care

• Do not use any form of treatment unless you find
  a living, moving louse.
• There are two treatment options

8
Self Care Lotions using insecticides

• Check all close family/ friends by the wet
  combing method and treat anyone who is found to
  have lice at the same time, to prevent
  re-infection.
• Ensure you have enough lotion to treat all those
  affected and follow the instructions on the
  packet carefully.

9
Self CareThe Bug Busting treatment method

• This aims at systematic removal of live lice by
  combing through the hair and physically removing
  any lice found.
• Success depends largely upon adopting a
  painstaking approach as described in the Bug
  Busting kit available from some pharmacies, and
  by mail order from Community Hygiene Concern
  (Helpline 0208341 7167)

10
Self Care, which is best?

• A recent study suggested that insecticide lotion
  was more effective than bug busting.

11
Self Care

• Alcoholic preparations work best
• If paying for prescriptions then treatment may be
  cheaper OTC.
• If pregnant - try bug busting
• If asthma, eczema or areas of broken skin on the
  scalp? use aqueous preparations

12
Alcoholic Preparations

• Malathion 0.5 in alcoholic base
• Rub 0.5 preparation into dry hair and scalp,
  allow to dry naturally, remove by washing after
  12 hours, repeat once at interval of 7 days.
• 50ml per person
• Phenothrin 0.2 in basis containing isopropyl
  alcohol 69.3 (Full Marks lotion)
• apply to dry hair, allow to dry naturally
  shampoo after 2 hours, comb wet hair

13
Aqueous preparations

• Malathion 0.5 in aqueous base
• Rub 0.5 preparation into dry hair and scalp,
  allow to dry naturally, remove by washing after
  12 hours, repeat once at intervals of 7 days.
• Phenothrin 0.5 in an aqueous basis (Full Marks
  liquid)
• apply to dry hair, allow to dry naturally
  shampoo after 12 hours or next day, comb wet hair

14
Bug Busting

• This requires the use of a plastic detection comb
  and hair conditioner. The methods typically
  involve meticulous combing with the detection
  comb (probably for at least 30 minutes each time)
  over the whole scalp at 4-day intervals for a
  minimum of 2 weeks.

15
Transmission

• Transmission of head lice requires close contact
• Head lice can only survive for 48 hours off the
  scalp. The eggs can survive for up to 10 days off
  the scalp, but will not hatch at room
  temperature.
• Transmission can occur directly via close
  contact, or indirectly via hats, combs and
  brushes or scarves. Soft toys and blankets are
  also vehicles for transmission in schools.
• Epidemics often sweep through classrooms. It is
  sensible to inspect the hair of classmates and
  family members if infestation is found.

16
Head Lice

• References Prodigy, BNF and NHS Direct
• 2002