Head Lice
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Head Lice

Head lice are parasitic insects called Pediculus humanus capitis found on the heads of people. 



Reservoir
Humans


Life cycle
They sexually mature within 8 – 10 days after hatching.

There are 3 stages:

  • Nits: Head lice eggs. They are oval, yellowish white and are hard to see and may be confused with dandruff. Eggs usually hatch in 7 – 10 days although this varies according to the temperature needed for them to hatch.
  • Nymphs: They are the baby lice and take 7 – 10 days to mature to adults.
  • Adults: They are the sesame of a sesame seed and are capable of laying eggs. The adults have 6 legs with hook-like claws to hold onto the hair with.

The life cycle of the louse is about 28 – 30 days.


Mode of Transmission
Spread is mainly by head-to-head contact but can also be transmitted through sharing combs and headgear. They do not live in bedding, furniture or clothes. 


Signs and Symptoms

  • Itching, generally behind the ears and at the back of the neck.
  • Irritability
  • Sores can be seen on the head resulting from scratching.\


Diagnosis

Presence of scalp pruritus and nits close to scalp is highly suggestive. Isolation of live lice on wet combing with nit comb is confirmatory.


Control and Prevention

  • Infected children should be excluded from school until treated. They should be allowed back to school once the first treatment is instituted. School mates who are not infected but are in contact with infected children do not require treatment.
  • Routine screening at schools and by parents at homes.
  • Educate about good hair care and good general hygiene.

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