.How is head lice infestation diagnosed ?

Head lice infestation is diagnosed by looking closely through the hair and scalp for nits, nymphs, or adult lice. Nits are the easiest to see. They are found "glued" to the hair shaft. Unlike dandruff or hairspray, they will not slide along a strand of hair. If you find nits more than 1/4 inch from the scalp, the infection is probably an old one.


Nymphs and adults can be hard to find; there are usually few of them, and they can move quickly from searching fingers. If lice are seen, finding nits close to the scalp confirms that a person is infested. If you are not sure if a person has head lice, the diagnosis should be made by the local health department or a health-care provider, school nurse, or agricultural extension service worker.

Do head lice cause harm ? 


Head lice rarely (if ever) cause direct harm, and they are not known to transmit infectious agents from person-to-person. Thus, they should not be considered as a medical or a public health problem. These lice may occasionally be burdensome because of annoyance; their presence may cause itching and loss of sleep. The louse's saliva and feces may sensitize people to their bites, thereby exacerbating the irritation and increasing the chance of secondary infection from excessive scratching. 

The greatest harm associated with head lice results from the well-intentioned but misguided use of caustic or toxic substances to eliminate the lice. A few lice on the head should not cause alarm; rather, they present an opportunity for parents to spend the needed time with their children in order to find and remove the offending insects. Grooming can be an effective method to remove lice, and engenders several associated physiological and behavioral benefits as well. Because of unfounded fears, some parents have suggested that children refrain from sharing protective batting or biking helmets. The miniscule risk of acquiring lice from such devices pales in comparison to the hazards averted by helmets.