How are lice and dandruff different?
Lice and dandruff are different conditions with differing underlying causes and treatments.
- Cause: Dandruff is caused by a fungus called Malassezia globosa. Your scalp reacts to this microbe by shedding the outer layer of the skin in the form of flakes. You can get lice when your head touches the head of someone who has been infested with lice. Itching is caused when head lice bite you and release their saliva. It is not caused by poor hygiene as misunderstood by many people.
- Risk factors: In the United States, infestation with head lice is the most common in children between the ages of 3 and 7 years old. Anyone who comes in head-to-head contact with someone who already has head lice is at the highest risk. Additionally, someone who uses personal wear such as hats, scarves, coats, combs, brushes or towels used by an infected person is at a risk of head lice. Dandruff usually begins in young adulthood and continues through middle age. People who do not wash their heads often are more likely to get dandruff due to the buildup of oil on the scalp. Sensitivity to certain hair care products can also put you at a risk of a red, itchy and scaly scalp.
- Appearance: Dandruff looks like flakes of white or yellow skin on the scalp and hair. The scalp appears dry and red patches may appear on the scalp. If you have lice on your head, lice eggs (“nits”) attached to the hair fiber appear as small white bumps on the hair. There may be red itchy bite marks.
- Location: Dandruff is not localized and can be found everywhere on the scalp. Head lice are usually found on the scalp, behind the ears and on the back of the neck.
- Treatment: Dandruff can be easily removed, but the nits of head lice are firmly attached to the hair shaft. The treatment of dandruff involves washing the hair often with a gentle cleanser or using a medicated (zinc pyrithione and ketoconazole) anti-dandruff shampoo once or twice a week or washing the hair often. Dandruff disappears in the first wash itself. To prevent it from reappearing, washing the hair often is recommended, which removes oil from the scalp and helps prevent the buildup of dandruff. Head lice rarely go away in the first wash. A dedicated therapy of four to six weeks that’s targeted to kill the lice is needed. The nits also need to be destroyed along with the lice. For this, first, you need to use an over-the-counter pediculicide that can be in the form of a shampoo or lotion, which kills the hatched lice. Then, you’ll need to use a special fine-tooth lice comb to get rid of the eggs.