Even just the word "lice" is enough to send most people into a hair-checking frenzy, and with good reason: Lice just sound gross.
But while head lice seems to run rampant among children—up to 12 million infestations happen each year in the US among children 3 to 11 years old—lice in general can show up on anyone, anywhere, at any time. Here's everything you need to know about lice, including symptoms and treatments, according to dermatologists.
What exactly are lice?
Bad news: Lice are actually tiny parasitic insects that can be found on your head, pubic hair, and body—and, despite being slightly different, they all have one mission: to live on your body and feed on your blood (they need it to survive), according to the Centers for Disease Control and Prevention (CDC).
All types of lice have three forms: Nits, which are lice eggs; nymphs, which are immature lice; and adult lice, which are fully-grown and about the size of a sesame seed. But even different types of lice—head, pubic, and body—look slightly different from each other, Joshua Zeichner, MD, dermatologist at The Mount Sinai Hospital, tells Health.
Head lice, which are actually called Pediculus humanus capitis, are tall and thin, and attach themselves to the hair shafts on your head, says Dr. Zeichner.
Body lice, ake Pediculus humanus corporis, are similar in shape to head lice, but attach to the fabric of clothing and then travel back and forth to your skin to feed on you.
Pubic lice, which are also called Pthirus pubis, are short and squatty (sometimes called “crabs” because of their shape), and attach to coarse hair on your body; this includes pubic hair but also facial hair, eyebrows, eyelashes, and armpits.
But, as far as symptoms go, they're pretty much the same for all types of lice: Itching and mild skin irritation because of the itching, Rajani Katta, MD, a dermatologist at Houston Methodist, tells Health. The CDC also points out that you may see small bite marks, sores, or bruises in cases of body or pubic lice.
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So, how do you get lice?
All forms of lice are contracted through direct or intimate contact, according to Dr. Zeichner. (So not usually not by shaking hands with someone in passing.) Beyond that, how you contract lice depends on the kind of lice you’re talking about.
Head lice, for example, are transmitted pretty easily through shared clothing, hats, hairbrushes, or bedding—and body lice spreads in much the same way.
Pubic lice, on the other hand, is a sexually transmitted infection (STI), meaning you get them from sexual contact with an infected person. You could also get them by sharing undergarments or bath towels with an infected person, but again, you can’t really contract them via passing contact. Per the CDC, you can’t get pubic lice by sitting on a toilet seat because it’s a pretty inhospitable environment for the insects.
Kids are ripe targets for head lice because of their close proximity to one another in classrooms and day cares, but Dr. Katta says it’s important to remember that having head lice is not a sign of bad hygiene or dirtiness; spreading head lice can be as simple as sharing a hair elastic or beanie among friends.
However, Dr. Katta warns that finding pubic lice anywhere on a child’s body (even if it’s just their eyelashes) could be a sign of inappropriate sexual contact and should be addressed immediately.
How can youtreat or get rid of lice?
Generally, all lice is treated in the same way: with a topical prescription medication designed to kill the lice, used at least twice—once to kill the adults and a second time, several days later, to kill any nits that have hatched since the first treatment. The medication for head lice, called pediculicide, should be applied according to the instructions, per the CDC. You can also comb any of the dead or dying lice out of your hair with a fine-toothed comb, says Dr. Katta.
For pubic lice, lice-killing lotions that contain active ingredients called permethrin, pyrethrins, or piperonyl butoxide, can be applied to the area. Dead or dying lice, again, can be removed with a fine-toothed comb of your fingernails. But, as a reminder: With pubic lice, you should warn all sexual partners from the previous month that they're at risk for infection; and it's a good idea to abstain from sexual contact until you're given the all-clear (pubic lice can clear up in eight to 10 days).
The treatment for body lice is a little different, and mainly includes improving the personal hygiene fo the infected person, per the CDC. Clothing, bedding, and towels used by the infested person should also be washed using hot water (at least 130°F) and machine dried using the hot cycle—but that's true for most other types of lice infestations, as well.
Can you prevent lice?
When it comes to any type of lice, the best prevention is to keep your personal belongings to yourself (and not borrow anyone else’s stuff, either). There’s all kinds of urban legends about people catching lice from airplane headrests or toilet seats, but that doesn't happen (remember: lice need blood to survive). With pubic lice, it's obviously wise to steer clear of sexual contact with an infected person, as well.
And if you or someone in your home has recently had a lice infestation, you don't have to totally redecorate, says Dr. Katta. "After an infection, wash clothing and bedding in hot water and dry it on high heat, if possible,” he says. “Look around for stray hairs [and vacuum if needed], but you don’t need to go crazy cleaning carpets and furniture."
Other than that, don't stress about lice until you absolutely have to.