Lice infestation is universal. Head lice have co-existed with humans for two thousand years. They have been observed in the sarcophagus of well-preserved Egyptian mummies, in tombs that also contained fine-toothed combs to remove head lice. They do not pay heed to social, economic or geographic boundaries. A millionaire’s offspring as well as the child of a slum dweller can both be seen scratching their heads. Closer inspection may reveal lice scurrying along hair shafts, or white nits (eggs) closely attached to the hair.
Infestation is a social stigma. The child is perceived as â€œdirtyâ€ and the parents are seen as negligent caretakers. Neither of these statements, however, is necessarily true. Lice can survive submersion, oiling, shampooing and extremities of temperature.
Head Lice or Pediculus capitis (which literally translates to â€œlice of the headâ€) have not changed or evolved much. They are still small, brown insects with a tough outer coat and tapering legs adapted to cling tenaciously on hair shafts. They can survive huge climatic variations and lay dormant for up to 10 days. They cannot fly or jump; they move from one human being to another by crawling along the hair as heads move into close contact, or by walking along walls, floors, furniture and bedding. They are also very fastidious and host specific they can survive only on the scalps of human beings, and not on other animals.
Head lice themselves do not cause disease. But they cause intense itching which can interfere with sleep, concentration and efficient functioning. The scratching can cause secondary bacterial infection. This, in turn, can lead to painful enlargement of the lymph nodes in the neck.
In traditional societies, people found a way around this problem. Some families regularly went on pilgrimage. Their houses were cleaned and then locked. Unable to obtain a human blood meal, the lice starved to death within 10 days. And at the pilgrimage site, the whole family was tonsured. Thus, no hair meant no lice!
Bug-busting fine-toothed combs are readily available. They are safe and effective. The hair should be well oiled and all the tangles removed before combing. Most of the lice slip off with this treatment. The action has to be repeated every alternate day for two weeks till no lice are seen.
Chemical lice treatments are also available. They contain pyrethroids, permethrin, lindane or malathion. These compounds may be available as lotions or shampoos. The treatment must be repeated after 10 days.
About 17 per cent of lice are resistant to insecticides. Repeated treatment, using higher-than-recommended doses will not work. In fact, they may even be harmful and signs of toxicity may appear.
A combination of insecticide treatment followed by bug-busting combing is very effective.
Lice reproduce efficiently and explosively. Each couple can produce 100 eggs in a lifetime. Each egg hatches after eight days and the little bug develops into an adult in around 10 days. Unless the eradication treatment is repeated every 10 days, new lice will repopulate the hair.
After some time lice may reappear. This may be due to reinfection from another person or repopulation from lice that survived the original treatment.
If lice have gravitated to the eyebrows and lashes, they should be very carefully manually removed. Chemicals should not be applied.
Natural compounds are advertised for lice treatment. Some are neem-based. There may be others that contain organic pesticides in unregulated and dangerous doses. Before applying them, please read the fine print carefully.
Egg white and motor oil do not have any action on lice. On the contrary, they may cause hair loss.
Kerosene kills lice and nits. But it is also a dangerous, highly inflammable compound and therefore should not be used.
â€œLiceâ€ is actually a generic term that loosely refers to head lice. Insects from the same family, called Pediculus humanus or body lice, can also be found on the body (not the head), in areas where there is overcrowding, homelessness and poor hygiene. These lice cause itching, particularly around the waist, groin and upper thighs. There may be an allergic reaction that aggravates the itching. The skin may eventually become discoloured. Secondary bacterial or fungal infection may occur.
Unlike head lice, body lice can cause typhus and relapsing fever.
Regular bathing, clean clothes and application of lotions or creams containing pyrethroids, permethrin, lindane or malathion will kill the lice.
Crabs or pubic lice (Pythiriasis pubis) are usually spread through sexual contact. They can also spread through infected bedding. These lice cause intense intolerable itching in the genital area. They also respond to the lotions and shampoos containing pyrethroids, permethrin, lindane or malathion.
It is possible to get rid of all types of lice provided the cycle of reinfestation is broken and good personal hygiene maintained.
Source:The Telegraph (Kolkata,India)