Head Lice and Scabies During Pregnancy

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Pregnancy is a time for lots of new symptoms. Thus, if you find yourself with itchy skin, you might just decide that it comes with the territory. But if you are very itchy, and the itching is associated with a rash consisting of tiny red dots and lines, it’s time to visit your provider: you may have a condition known as scabies.

Like scabies, pediculosis, or lice, can also be an itchy problem. But it’s something you might not notice until you’ve had it for a while. Then suddenly, one day you might see something moving in your hair. Or maybe there are just little white or brown dots in your hair. It’s a diagnosis you’d probably rather not be able to make, but not too many other things look like lice.

Just talking about these two conditions is enough to get anyone scratching. And although they are somewhat different in many ways, scabies and lice have much in common. They’re both due to a small insect. Both can be uncomfortable but are not really dangerous. Both are pretty common. Finally, both are the subjects of much folklore regarding who gets them and how they are treated.

One myth to address right off the bat: scabies and lice are not the result of being unclean! People with good hygiene are subject to getting infested (i.e., getting the bugs on their person). Now that we’ve looked at what the conditions share, let’s look at them individually.

Lice

Lice are actually small mites. In the United States you are mostly likely to encounter head lice, known by species as pediculus humanus capitis. This is most commonly brought home by elementary school-aged children. People might also occasionally encounter pubic lice, or phthirus pubis, which is sexually transmitted. Other types of lice are rare under conditions of normal hygiene.

These common varieties of lice are picked up by direct contact. Contrary to popular belief, they do not jump a distance to infect people. They can, however, live on surfaces for up to 2 days and are sometimes picked up that way.

Talking about head lice, the type you’re most likely to see: the louse lays eggs, which take about a week to hatch. From there, takes about 2 to 3 weeks to grow into adult lice. They’re about the size of sesame seeds, and you can often make the diagnosis at home by seeing a moving mite. Eggs are a little more confusing: they may be yellow, white or brown, may blend right in with the hair, and can often be confused with other things (dandruff, for example).

The major other symptom than infested individuals are likely to encounter is mild to moderate itching, usually about 4 to 6 weeks after infestation. The louse feeds on the scalp for blood, and its saliva irritates the skin. Occasionally there is a little red rash; anything more than that may mean bacterial infection due to scratching.

Scabies

Like lice, scabies is due to a small mite; in this case it’s known as saroptes scabei var hominis. Once again, the mite infects humans who come in direct contact with it, either from another individual or a surface on which the insect is resting. However, it can only live off of humans for 24-36 hours.

Once exposed, it takes 4 to 5 weeks for an infected human to experience symptoms. An incredibly itchy rash develops—it might be the worst itching you’ve ever experienced. The rash can take several forms but most commonly consists of little reddish-pink bumps. Red lines, or “burrows,” may be present due to the movement of the mite under the skin.

Providers vary in how they diagnose scabies. It very commonly occurs in creases and folds of the skin, such as the armpits and groin. A particularly suspicious area for scabies is the area between the fingers, particularly at the base. Except in infants, it usually doesn’t involve the face.

Your provider may choose to make the diagnosis based on the appearance of the rash as well as the symptoms, especially if there is known contact with the scabies mite. Some providers may choose to take a little scraping of the skin and examine it under a microscope for the mite.

Treating the Bugs in Pregnancy

For the most part, the treatment of scabies and lice is very similar. In both cases, there are special considerations for pregnant women since the wrong medicine has the potential to damage an unborn child. Fortunately, there is a variety of medicines that are directly applied to the skin.

Permethrin is thought to be safe an effective for both scabies and lice, and that is likely to be a first choice for treatment. Also good for lice, and thought to be generally OK during pregnancy, are malathion and spinosad. Other medications are possible choices but may have safety (in pregnant women) or effectiveness issues. In particular, an oral medication known as ivermectin is less recommended due to the finding of some birth defects in animal studies (albeit in high doses). A topical (applied to the skin) form of ivermectin is also available and is sometimes used, though perhaps less so in pregnancy.

Several years ago, a topical medicine called lindane was a high choice for both lice and scabies. This is no longer recommended because it can affect nerves, and there are now safer medicines.

“Natural” non-medication treatments won’t work for scabies. Lice, however, can occasionally be treated using a wet comb to remove lice and eggs. Other treatments you might have heard of, such as mayonnaise, haven’t been shown to be effective.

If you think you have head lice or scabies, you certainly want to check with your provider, as different treating providers may have different preferences, and new safety and effectiveness data (as well as new medicine) emerges all the time. Individual providers also differ as to whether people need to be treated a second time and whether family members need to be treated. In most cases, clothing and bedding that might have come in contact with the insect should be washed in the hottest water it will take; things that can’t be washed can be put away for several days. Finally, in the case of lice, it’s worth going through hair with a special comb to remove the eggs, or “nits.”

When we’re talking about lice and scabies, it’s hard to say what’s worse: the infestation itself, or the very idea of it. Fortunately, there are good treatments out there. And rest assured: it’s nothing to be ashamed of!

Stan Sack
Dr. Stan Sack has 29 years’ experience as a primary care pediatrician in Massachusetts and Florida. A medical writer since 2015, he enjoys blogging on topics that are on parents’ minds but are covered less often in books and on websites. He lives in the Florida Keys with his family and enjoys healthy cooking, fitness activities and singing in his spare time.

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