What is it?
Pediculosis, popularly known as lice, is a contagious infestation caused by small parasitic insects that populate areas of the body with hair or clothing They are flat, without wings and feed on human blood. They are very contagious and sometimes very difficult to eliminate. They don’t transmit any type of disease.
Their life cycle lasts about 30 days in the head, on the contrary they do not survive more than 24/48 hours without a human host. The phases are:
- Nits: are the eggs of the lice. They have an oval form, of yellow-white color and are glued to the scalp near the root with a sticky substance secreted by the females. They need heat and a certain distance from the root to survive. It takes about 7-9 days to become nymphs. They are confused with dandruff, with the difference that nits aren’t easily removed.
- Nymphs: immature lice. They look very much like an adult louse, but they are smaller and their reproductive organs aren’t yet mature. They feed on human blood and it takes about 9-12 days to become adult lice. Normally they aren’t the focus of contagion, since they don’t go from head to head.
- Adult lice: they survive 30 days on the scalp. They are gray colour parasites and with 6 legs. They neither jump nor swim. Females are larger than males and are able to generate more than 200 eggs throughout their life. They feed on blood 5 times a day.
Types
There are several types of lice. Humans can be infested by three types:
- Head lice (Pediculus humanus capitis)
- Body or clothing lice (Pediculus humanus corporis)
- Pubic lice or crab louses (Phthirus pubis)
Who does it affect?
Anyone can become infected, as it is very easily spread by direct contact.
Infestations are common in:
- Pediculus humanus capitis: mainly in children of school age.
- Pediculus humanus corporis: is more frequent among indigents.
- Phthirus pubis: usually occurs in sexually active people.
Cause
Lice can’t jump, or fly. The contagion is produced by direct contact with the infested person or with one of his personal objects (comb, brush, clothes, pillow). It has nothing to do with hygiene.
Symptomatology
The characteristic symptoms are:
- Itch: is the most common symptom experienced by a person infected. It can take two to three weeks or more from the infection until the person begins to notice the symptoms. Pruritus is due to an allergic reaction of our immune system to lice saliva. When the lice sting to feed through the scalp, it injects a toxin that is irritant and anticoagulant.
- Eczema: the scratching causes a redness of the area and in some cases eruptions develop.
Treatment
When lice are identified, immediate action should be taken to prevent them from proliferating with anti-lice lotions and conditioners containing permethrin and periodic and manual revision to ensure that no lice or nit remain.
It’s recommended to continue the treatment for 7-10 days to ensure that there isn’t any egg or living adult justify.