What’s the difference between lice and dandruff?
It’s very easy to tell when hair is dirty; it’s greasy, smelly, and sticky, too. If you spot little white dots as well, you might also think there’s lice or dandruff—but they aren’t the same thing. Although lice and dandruff both cause itching, that’s where the similarities between the two end.
Head lice are small parasitic bugs that live on the scalp and feed off your blood, according to Benjamin Garden, MD, a dermatologist practicing in Chicago. The insects lay yellow, brown, or white, eggs or nits in the hair. Dandruff, on the other hand, has nothing to do with bugs but rather inflammation and dryness in the scalp. The inflammation causes itchiness, redness, and what dermatologists call “scale.” No, not like fish scales, but tiny white flakes of dry scalp. Another difference is that dandruff isn’t contagious while lice are easily contagious through sharing brushes or getting close to hair with lice. (Don’t miss these eight ways to treat head lice.)
How can you see the difference between lice and dandruff?
Dandruff flakes easily come off of the hair, while nits usually stick on the hair, says Shari Lipner, MD, a dermatologist at NewYork-Presbyterian and Weill Cornell Medicine. It’s best to have someone else check your scalp with a mirror and comb to get a good look, especially since it’s hard to see nits. Even after they hatch, the eggshell stays in the hair for several months, according to Dr. Garden. (Are you suffering from thinning hair? Doctors recommend this at-home trick.)
Dandruff scale is on the top of the scalp, but lice only lay nits on hair strands—not the scalp, Dr. Garden says. Similarly, dandruff is usually across the whole scalp. Head lice are typically behind the ears and on the back of the neck, with exceptions for extreme cases where nits are everywhere.
The treatment is also very different
Treating lice and dandruff are very different. Dr. Lipner says there are over-the-counter medicines and prescriptions to treat lice. You’ll need to comb the nits out of the hair, too. Make sure to wash brushes, combs, linens, and vacuum all carpets and rugs. As for dandruff, Dr. Garden recommends patients alternate showers using a shampoo with salicylic acid, which helps break down the scale, and ketoconazole, which helps decrease inflammation.
If all else fails, it doesn’t hurt to check in with your dermatologist about either or both of these conditions. If it turns out you have dandruff and not lice, here’s everything you need to know about dandruff.