Lice of head (head louse) medically is known as Pediculosis Capitis, is seen in young girls with long hairs. Pediculosis Corporis is found on body known as body louse is found in those persons who lives untidy, here louse lives on clothes and stick to body only for feeding.
Patient complains of itching, due to itching person used to scratching sometimes leading to secondry infections.
Diagnosis is made by seeing the nits in hairs or seams of cloths.
Spread: Head lice spread by head-to-head contact (which children get a lot of when they are playing together).
Treatment: one percent permethrin is used to rinse on hairs, it has to be repeated since new lice hatch from nits. Clothes should be washed and ironed. Shaving of hairs is also good alternative.
Watch out very interesting and hilarious video from youtube embeded below giving all details of head lice, its life cycle and treatment
Note: In Indian villages there is a habit of picking head louse with hands and crushing louse on nail bed, this habit can cause relapsing fever as it is transmitted by louse being crushed and rubbed into abraded skin, this disease is very severe and it tends to occur as epidemics. Relapsing fever is caused by Borrelia recurrentis which is a bacteria while louse act as vector.