Detecting Lice

	Egg/Nits: These are lice eggs laid by the adult female louse at the base of the hair shaft near the scalp. The eggs are firmly attached to the hair shaft and are oval-shaped and very small and hard to see. Eggs vary in color from clear to light brown to yellowish-white. They are often confused with dandruff, scabs, or hair spray droplets. Eggs are usually located no more than 1/4in (.635cm) from the base of the hair shaft.
	Nymphs: A nymph is the immature louse that has recently hatched from the egg. Nymphs look like adult lice, but are smaller. Nymphs mature after 3 molts. Like adult lice, nymphs must feed regularly on human blood.
	Adults: The fully grown adult louse is about the size of a sesame seed, has six legs, and is tan to grayish-white in color. To survive, adult lice must feed on blood. An adult head louse can live about 30 days on a person’s head, but will die within 24-48 hours if it falls off a person.

 Detection and Diagnosis of Lice

Head lice and eggs are found almost exclusively on human head hair and the scalp, frequently around and behind the ears and near the neckline at the back of the head. Head lice and eggs are sometimes also found on the eyelashes or eyebrows, but this is uncommon. Misdiagnosis of head lice is common.
        
The best diagnosis is by finding a live nymph or adult louse on the scalp or hair of a person. Adult and nymphal lice are very small, move quickly, and avoid light, so they may be difficult to find. Using a fine toothed louse comb helps in correctly diagnosing head lice.  When doing a wet comb - wipe on a white paper towel.  Lice Nits (eggs) will look like little slivers ranging from cream to brown in color.  It can be difficult to spot nits because they are extremely small.

Nits resemble dandruff in appearance, however they can easily be distinguished from dandruff, as they are attached to the hair follicle and will not move upon agitation. Usually inspections are conducted with high lighting and a magnifying glass, and hair ties and wooden sticks are used to separate and comb through hair. Lice move very quickly, so adults and nymphs can be hard to spot, but finding any nits close to the scalp, behind the ears or near the neck is a good sign that an active infection is present. If nits are found more than a quarter of an inch from the scalp, then the infestation may be expired and no longer requires treatment. If a conclusive diagnosis cannot be made at home, then the assistance of a medical professional should be sought.

Eggs that are attached within 1/4in (.635cm) of the base of hair shafts suggest the person may have an active infestation. Eggs that are found more than 1/4in (.635cm) from the base of hair shafts are almost always non-viable eggs (dead or empty egg casings).

If no live nymphs or adult lice are seen, and the only eggs found are more than 1/4in (.635cm) from the scalp, the infestation is probably old and no longer active.