7AM - MIDNIGHT | 7/365

How to Identify Nits

How to Identify Nits
Updated on 
January 30, 2019

How do I know if what I am looking at are nits or dandruff or something else? That is a question that we frequently hear from parents in McKinney and Allen and surrounding areas. It can be tricky to identify the differences.

We often get phone calls from parents who are seeing some “things” in their child’s hair but they are unsure what they are looking at. This is for good reason. It can be confusing for an untrained person to differentiate among nits, hair casts, DEC plugs, and dandruff. What?? It’s true; not all whitish “things” in the hair are nits.

Nits (lice eggs) may appear to be white in the hair, which can be confusing to the untrained eye. Nits are actually a translucent shell covering a brown baby louse. While dandruff is flaky and pulls easily off the hair shaft, nits are hard and are stuck to the hair with glue. In addition, there may be DEC plugs which are white and sticky and cling to the hair. DEC plugs are secretions from overactive oil glands. And let’s not forget hair casts, which are white, elongated, and thin.



Nits are lice eggs; each nit has a translucent shell that houses a little brown baby louse called a nymph. In the hair, nits may take on a whitish appearance but when they are placed against a white background, nits will look brown not white. The shell of the nit is very tough and it really protects the growing bug inside. No chemical products designed to eliminate lice are able to pierce through the shell; therefore the only way to eradicate lice is to physically pull out the nits. This is not easily done as the nits are cemented to the side of the the hair.

Nits are about the size of a sesame seed, although when they are first laid they are microscopic. They grow over 10 days and then they hatch. Each nit is round on one side and pointy on the other with a tail-like antenna coming out of the pointy end. Nits need the temperature of the human head to live as well as human blood, therefore viable nits are within 1/4 inch of the scalp. If you find nits that are down the hair shaft, they are hatched remnants that have not fallen off. There is no live bug inside. Nits camouflage in the hair and can be difficult to find. A trained lice technician is best able to locate the nits in the hair

DEC Plugs

Many people mistakenly assume that bright white sticky things in the hair are nits when, in fact, they are DEC plugs.

If a parent reports ongoing problems with nits without ever seeing a louse, it may be a sign of confusion in determining nits versus common hair debris. This debris is often referred to as DEC plugs and hair casts.” Headlice.org


Desquamated epithelial cells or DEC plugs can show up in the hair when oil glands in the scalp become over active to make up for the drying effects of chemical treatments. If you have been using OTC or prescription lice treatments and come face to face with a scalp covered with white sticky blobs, you may very well be looking at DEC plugs. Because there may be a lot of them, they can really scare a parent who gets an eyeful of them. They are very white, irregularly shaped pieces of fat cells that stick to the hair shaft.

Hair Casts

Like DEC plugs, hair casts are often mistaken for head lice. Also like DEC plugs, hair casts are harmless. Many people have them and don’t know it. In fact, they are often found on the hair when someone is searching for head lice and nits. Pseudonits is the technical name; they are white, narrow, and cylinder-shaped. They are a lot easier to remove and are whiter than nits and they wrap around the whole hair shaft instead of just sticking to one side. Hair casts are 2-7 mm in length. Like DEC plugs, if a person has hair casts, there are usually a lot on the hair. They may accompany psoriasis or seborrhea. Hair casts are basically debris that is found in the hair.

Casts seem to be most common among young adults. The pathogenesis is often not clear, but their presence can be associated with pityriasis amiantacea, seborrheic dermatitis, hair nodes, scalp psoriasis, hairstyles with much traction and also the use of hair sprays. All these conditions lead to formation of more consistent root sheaths, which do not disintegrate during the hair growth.

They can be easily slid along the hair shaft. This characteristic is of paramount importance in their diagnosis and helps in differentiating them from other scalp disorders, such as pediculosis capitis...As is often the case, hair casts may initially be misdiagnosed as the nits of pediculosis capitis...” International Journal of Trichology




Like DEC plugs and hair casts, dandruff is a harmless type of skin eczema, also called Seborrheic Dermatitis. Dandruff derives from an overproduction by the oil glands on the scalp. Dandruff is white and flat and flakes off the hair. On some heads, it is found only in a few areas while other heads are covered with it. Like lice, dandruff may cause itching. Also like head lice, it is not a result of poor hygiene.

Here are some key points about dandruff.

  • Dandruff is a common condition, but it can be embarrassing and difficult to treat.
  • It is not related to hygiene, but washing and brushing the hair can help remove old skin flakes.
  • Risk factors include having certain skin or medical conditions and the use of inappropriate hair products.
  • Various treatments are available over the counter, but more severe cases should be seen by a doctor.”

Medical News Today

People who have dry skin, sensitivity to yeast, overwashed hair, eczema, and even Parkinson’s disease are more susceptible to dandruff. Men are more likely to have dandruff than are women.

When trying to determine what you are looking at in the hair, here is a trick: to determine if what you are looking at are nits, hair casts, dandruff, or DEC plugs stuck to the hair, pull them out and place against a white background. If what you are looking at is brown and oval with a pointy front, you have pulled out nits. If they blend into the white background then you have found dandruff, hair casts, or DEC plugs.

If you are unsure, call LiceDoctors at 214-382-9727 and we can help you. We may ask you to send a picture, however, the best way to check is in person and we always have a technician available to help you day or evening, 365 days a year, anywhere in the McKinney area.


We provide a friendly in-home lice removal service

Book your appointment today


Family and Head Lice
Updated on 
November 12, 2020

Family and Head Lice

The chance of a case of head Lice spreading within a family is very high. In over 75% of cases, if one child gets it then either mom and/or a sibling gets it as well.

Read more
About Head Lice Infestations and Boston Lice Removal
Updated on 
November 12, 2020

About Head Lice Infestations and Boston Lice Removal

As with other geographical areas across the US, young children in Boston face lice infestations in their classrooms through out the school year and in their camp groups during the summers.

Read more