Both nits and dandruff cause itching of the scalp, but the similarities stop there. The causes of nits and dandruff, as well as the treatments to treat these conditions are vastly different. Nits are the eggs of lice. Dandruff is simply dry skin on the scalp.
Lice are small parasitic insects that feed on blood. They do not jump or fly around. However, lice are contagious and are easily spread by close personal contact. Lice can live outside a human body for only about one day, but the nits can live for seven to 14 days. The nits are tiny ovals, a bit smaller than a grain of rice. They attach to hair with a waterproof glue-like substance. They cannot be washed out with water nor blown out with a hair dryer. The nits do not necessarily cause itching, but when they hatch, the lice crawling around on the head, feeding off the blood from the scalp, cause intense itching. One louse can lay as many as 100 eggs.
Treatment for Lice
There are several treatments for lice. Several over-the-counter cream rinses are available that use chemicals such as pyrethrin or permethrin. However, in some regions, lice are resistant to these chemicals. The procedure for using the non-prescription treatments involves washing the hair with regular shampoo, without conditioner, followed by application of the pyrethrin or permethrin containing cream rinse. After a designated period of time, the cream rinse is washed out, and the dead lice and nits are combed out.
If the over-the-counter treatments are not effective, there are several prescription medications that can be used; for example, malathion and benzyl alcohol. A prescription shampoo called Lindane can also be used. However, increasing numbers of people have experienced lice resistant to this medication, and there are reports of serious neurological side effects also associated with it.
Tea tree oil may also be effective in treating infestations of lice. However, as reported by the National Library of Medicine in 2009, there have been no large, well-designed trials showing its effectiveness.
Dandruff is simply flakes of dry skin that slough off the scalp. The dry bits of skin that slough off as well as the dry scalp itself lead to itching. It is not contagious, and it is rarely serious. There are several known causes of dandruff. The most common dandruff is caused by simple dry skin, similar to the dry skin people experience elsewhere on their body during hot dry summers, for example. Other causes include a condition called seborrheic dermatitis, characterized by irritated, oily skin. Seborrheic dermatitis can occur on other areas of the body besides the scalp. The flakes are usually white or yellow. Infrequent shampooing can lead to buildup of oils and skin cells on the scalp. When the buildup is great enough, the cells start to slough off, causing dandruff. Other skin disorders that can affect the scalp causing dandruff flakes include psoriasis, an accumulation of dead skin cells, eczema and sensitivity to certain hair care products.These flakes are usually silver. There is also a fungus called malassezia. Usually, malassezia lives on adult scalps without causing issues, but in certain cases, it can grow out of control, irritating the skin and causing more skin cells to grow. The excess cells flake off as dandruff.
Dandruff is much easier to treat than lice. A mild, gentle cleanser is sometimes all that is needed. For more serious conditions, there are several over-the-counter medicated dandruff shampoos that are available. Medications in these shampoos can include zinc pyrithione, tar-based shampoos, salicylic acid, selenium sulfide or ketoconazole. For extremely stubborn dandruff, prescription-strength shampoos or steroid lotions are also available.
Features of Nits vs. Dandruff Flakes
It is easy to tell a nit from a dandruff flake. Nits stick to the hair quite aggressively. They are oval and are not easily removed. Dandruff flakes, on the other hand, are easily removed upon lightly touching or combing of the hair. These flakes can easily fall onto shoulders.