Medical Conditions

Head Lice

Head Lice (Scientific Name: Pediculus Humanus Capitas) are tiny, wingless grey/brown-coloured insects.  Adult head lice are generally 2-4 millimetres long – approximately the size of a sesame seed.  Conversely, head lice eggs (also known as nits) are barely one millimetre long and are white in colour.

Lice are parasites – they feed on human blood and cannot survive more than 48 hours (but often as little as 8-24 hours) without a human host.  Lice change colour whilst feeding, from grey/brown/black to a deep red, when full.

Head Lice are most common in children from 3-12 years old. This is the time when most children go to kindergarten or primary school and often play in close proximity to each other.  However, head lice can and will infect anyone, of any age or gender, with short or long hair.


Contrary to popular opinion that an itchy head is the first sign of head lice, the most common symptom is seeing or feeling head lice moving in your hair, or noticing the white nit cases in your hair or against dark-coloured fabric .  It is not the lice themselves that cause an itchy scalp, but irritation caused by lice faeces or saliva on your skin.