Emily Oster

9 min Read Emily Oster

Emily Oster

A Decision Tree for Ticks and Lyme Disease

What to do when you find one on your kid

Emily Oster

9 min Read

One Monday afternoon in the fall of 2019 I got a text from our babysitter which said something to the effect of, “I found a tick on Finn’s face. What should I do?” Obviously, I choose the adult option of “panic”. I rushed home, calling Jesse on the way, to look at it and remove it.

The tick, when I arrived home, was right there on his cheek, a tiny black dot. I realized, of course, I had seen this at breakfast and assumed it was dirt (yes, I bathe my children. Sometimes.). I pried it off and put it in a little plastic bag, then took some photos and tried to figure out what to do.

Thus ensued a week or so of serious tick research, involving several doctor calls, extensive searches of UpToDate and a long email exchange with Jesse about next steps. I was tempted to include that email exchange verbatim in this post, but I think actually seeing inside our work process might be a little too real.

The culmination of that, though, was a better plan for what to do if this happened again, which I’ll describe to you below. It was a good thing, too, since our family is apparently a bunch of tick magnets. Finn had another one a few weeks later, then I did, and finally Jesse. Only Penelope has been spared (so far; it’s only a matter of time.)

What is the problem with ticks? Is it all ticks?

Ticks can spread a number of different diseases but by far the biggest concern in terms of numbers is Lyme disease. Lyme is caused by a bacteria, which is spread through the bite of blacklegged ticks (sometimes called deer ticks). The disease causes fever, fatigue and — often but not always — a particular bulls-eye pattern skin rash. It can be treated with antibiotics. But: if left untreated (either through lack of detection or confusion about the cause) it can cause serious and possibly long-term health problems. It’s much harder to treat at this stage.

Conclusion: you do not want to get Lyme disease, or have your child get it.

Not all ticks spread Lyme; it’s only deer ticks. A little cheat sheet is below. Of note is that dog ticks are much bigger. But if you are not an expert you may need some help figuring it out (one pediatrician I talked to told me “most of the calls we get turn out to be dog ticks”).

Which is why you should save the tick, despite your presumed instinct to flush it or, in my husband’s case, microwave it.

In the spring, you’ll get a lot of active nymph ticks, which are especially good at spreading Lyme and are also tiny so even a very good parent could totally think they were dirt. Adult ticks are more common in the fall.

A chart with images of various kinds of ticks.
Atlantic Pest Solutions

I found a tick on my kid (or on me!) What do I do?

First, take it off. To do this, you can use the CDC method involving tweezers. OR: you can use the dizzy tick method, illustrated in this amazing video. I’ll wait. Don’t throw it away!

Second: think about the length of time the tick was possibly attached to the victim. Lyme disease is spread through a tick bite, not just a tick walking around, so it’s key to think about when the tick actually sunk its teeth in.

This may be hard to know (this is part of the value of tick checks – see below). But often you will have a sense of the timing. In our case (for example) we had been hiking in a tick-heavy area the Saturday before, and I had a photo making clear the tick was NOT on Finn’s face Sunday mid-day. It must have been somewhere else (in his hair? eww), crawling around looking for a good spot. But it clearly was there Monday morning, when I thought it was dirt. We effectively narrowed the time range to something like 6 to 18 hours of tick attachment time.

This is important because tick attachment time closely relates to the risk of Lyme transmission. One study found a 25% Lyme rate in bites with more than 72 hour attachment versus no cases in those with less. A second shows a similar difference between before and after 72 hours. Mice studies corroborate this, showing that before 48 hours of attachment time, transmission is extremely unlikely.

If the tick was attached for a limited amount of time (say, less than 36 hours), a good course of action is to keep an eye on it but not to do anything else. (You should probably still tell your pediatrician, just so they are aware.)

In the case where the tick is attached for longer (or you do not know how long it’s been), you’re at another decision node. Specifically: there is a question of whether to (A) wait and see if a Lyme-indicating rash develops and treat if it does or (B) treat in advance (“prophylaxis”), typically with an antibiotic called doxycycline.

The idea with option (B) is that this advance treatment would mean less likelihood of developing Lyme disease at all. There is a medium-sized randomized controlled trial (482 people) which demonstrated that this works, significantly lowering rates of later illness. However: the small size of the trial makes it hard to pin down exactly how protective the treatment was.

The argument for option (A) — just waiting — lies in the fact that most people who are bitten by a tick do not develop Lyme disease. Further, in 80% of cases a rash will show up as a symptom and, if it does, treatment is very effective at that stage (this number is perhaps 90% in children). Together, this means that treating everyone with prophylaxis entails a lot of unnecessary treatment, which raises concerns about over-use of antibiotics and, more immediately, has a reasonably high rate of side effects.

The argument for option B is that if one is in the 10 to 20% of people who get Lyme and do not show a rash, much more serious illness can develop. If early treatment can lower that risk, it might make sense.

There is no obvious answer here and medical advice seems to linger on trying to isolate prophylaxis treatment to cases where Lyme is more likely — if you can be sure it was a deer tick, if it was on for a long time, if it was engorged with blood and if you’re in an area with a higher prevalence of the Lyme-causing bacteria (New England, some of the Mid-Atlantic, parts of Minnesota and Wisconsin).

The non-obviousness of this choice means you surely want to discuss with a doctor. I talked to three I trust a lot and they all told me a version of the above, but noted that they try to learn a lot more about the case and also evaluate the level of parental anxiety.

Regardless of which option you go with, you still want to be alert for a rash. Which, by the way, isn’t going to itch or be raised or anything — it’s a flat rash with a specific bullseye pattern. Note this can be harder to see on the face or scalp and on darker skinned people, where it sometimes looks more like a bruise.

Confused yet? Here’s a little decision graphic.

A decision tree for what to do if you notice a tick on your child.

Prevention: Tick Checks and DEET

One of the things the above makes clear is that the best way to deal with this is to not have a tick attached to you for a long time. In a way, this is very reassuring since you can check for ticks and take them off if you see one. If you are living in a tick-heavy area, it is a good general habit to check everyone for ticks after any extensive time outside.

This just means looking at everyone totally naked and seeing if there are any odd-looking marks. It’s actually quite a bit easier with kids because they do not have a lot of body hair and old scars and moles. But you should also check adults! It sounds weird but, really, it is the easiest way.

You may also want to use insect repellent, which will keep ticks away to at least some extent (and also mosquitos, which are a whole other ballgame and I’ll leave for another day). But then people worry about DEET! Non-DEET repellents do not work as well but…is DEET a poison?

Technically, yes. And like all chemicals of this type, a lot of care must be taken with not ingesting it. But the concerns many parents have is that DEET may be a dangerous neurotoxin, even when used correctly.

In response, I give you this review article, entitled “Is DEET a Dangerous Neurotoxicant?” To which the answer (by their reporting) is “No”. The CDC and other official bodies (notably the AAP) also support the use of DEET-containing repellants, although they note that you do not need “100% DEET” and, in fact, recommend no more than 30% DEET in repellants. These recommendations are based on the fact that data doesn’t suggest DEET is a neurotoxin in normal usage.

Everyone urges some caution — you should be careful not to spray repellant at kids faces, or get it on their hands, or really anything in which they could ingest it. And like with sunscreen: if possible, clothing coverage is better than repellant. But DEET also works better than anything else so if you’re going to be in a very insect-infested area, it’s a reasonable choice.

A Final Word

My mom told me recently I should write a post on “What you should worry about.” Here it is! Ticks. I mean, don’t obsess about them. But would I think you are crazy for doing a tick check every day that your family is outside in the yard? No, I would not.

Thank you on this post to Dr. Lauren Ward (our pediatrician!), Dr. Lauren Allister & Dr. Adam Davis for their consultation and tick removal videos.

Two women stand on a balcony chatting. One is pregnant.

Feb 27 2023

6 min read

Your Best Parenting Advice

ParentData is 3!

Emily Oster
A line graph with pink, yellow, and blue dots representing life's ups and downs.

Feb 21 2023

3 min read

Wins, Woes, and Autism

Your stories for the week

Emily Oster
A toddler sits on a couch poking at an iPad and smiling.

Feb 16 2023

4 min read

Infant Screen Time and Academic Success

Infant screen time and breakfast cereal terror

Emily Oster
A teddy bear sits on a chair in a doctor's waiting room.

Feb 06 2023

11 min read

New AAP Guidelines on Childhood Obesity

What does the data tell us?

Emily Oster

Instagram

left right
Bug season is upon us. Besides annoyance, this can bring up safety concerns, particularly with ticks. They are carriers of diseases, most notably Lyme disease. So what’s the best course of action?

Prevention is key! I suggest:
⭐ Regular tick checks
⭐ Using bug sprays with DEET 
⭐ Wearing long sleeves and pants in the woods

Some parents worry about DEET, but repellants with up to 30% DEET are recommended by both the CDC and AAP. The data says you’re in the clear, so go for it. Enjoy your summer!

#parentdata #emilyoster #tickseason #bugbites #bugspray

Bug season is upon us. Besides annoyance, this can bring up safety concerns, particularly with ticks. They are carriers of diseases, most notably Lyme disease. So what’s the best course of action?

Prevention is key! I suggest:
⭐ Regular tick checks
⭐ Using bug sprays with DEET
⭐ Wearing long sleeves and pants in the woods

Some parents worry about DEET, but repellants with up to 30% DEET are recommended by both the CDC and AAP. The data says you’re in the clear, so go for it. Enjoy your summer!

#parentdata #emilyoster #tickseason #bugbites #bugspray
...

The list of what not to do while pregnant feels longer than a CVS receipt. At ParentData, we want to empower you to make the right decisions for you. 

What an amazing group of women, and an honor to speak at the #MomsFirstSummit debunking parenting myths. 

What are some pregnancy rules you chose to bend after being empowered by data?

#emilyoster #parentdata #pregnancyproblems #pregnancymyths

The list of what not to do while pregnant feels longer than a CVS receipt. At ParentData, we want to empower you to make the right decisions for you.

What an amazing group of women, and an honor to speak at the #MomsFirstSummit debunking parenting myths.

What are some pregnancy rules you chose to bend after being empowered by data?

#emilyoster #parentdata #pregnancyproblems #pregnancymyths
...

Looking for Memorial Day Weekend plans? Might be the perfect time to give potty training a shot. Potty training is notoriously difficult, and we unfortunately don’t have a lot of evidence-based guidance on what works best. So I asked the ParentData community to fill out a survey and share their knowledge — about 6,000 people responded.

👉Comment “Link” for a DM to an article that summarizes all of the best potty training advice we collected. 

Remember, you are not alone in the potty training struggle! It can be incredibly challenging, so please give yourself some grace.

#emilyoster #parentdata #pottytraining #pottytrainingtips #toddlertips

Looking for Memorial Day Weekend plans? Might be the perfect time to give potty training a shot. Potty training is notoriously difficult, and we unfortunately don’t have a lot of evidence-based guidance on what works best. So I asked the ParentData community to fill out a survey and share their knowledge — about 6,000 people responded.

👉Comment “Link” for a DM to an article that summarizes all of the best potty training advice we collected.

Remember, you are not alone in the potty training struggle! It can be incredibly challenging, so please give yourself some grace.

#emilyoster #parentdata #pottytraining #pottytrainingtips #toddlertips
...

We’re hiring an Associate Editor at ParentData! More details at my link in bio. Please share with the great writers and data-loving people in your network. 📊💻

We’re hiring an Associate Editor at ParentData! More details at my link in bio. Please share with the great writers and data-loving people in your network. 📊💻 ...

Do you brand things a certain way to get your kid to accept it? Like calling carrots “rabbit popsicles”? Or telling them to put on their “super speed socks” in the morning? Share your rebrands in the comments below! You never know who you might be helping out 👇

#emilyoster #funnytweets #relatabletweets #parentingjokes #kidssaythedarndestthings

Do you brand things a certain way to get your kid to accept it? Like calling carrots “rabbit popsicles”? Or telling them to put on their “super speed socks” in the morning? Share your rebrands in the comments below! You never know who you might be helping out 👇

#emilyoster #funnytweets #relatabletweets #parentingjokes #kidssaythedarndestthings
...

Have you ever panic-googled a parenting question when everyone else is asleep? If so, you’re not alone. 

Today is the first episode of a new biweekly series on my podcast: Late-Night Panic Google. On these mini-episodes, you’ll hear from some familiar names about the questions keeping them up at night, and how data can help. First up: @claireholt!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #emilyoster #claireholt #parentingstruggles #parentingtips #latenightpanicgoogle

Have you ever panic-googled a parenting question when everyone else is asleep? If so, you’re not alone.

Today is the first episode of a new biweekly series on my podcast: Late-Night Panic Google. On these mini-episodes, you’ll hear from some familiar names about the questions keeping them up at night, and how data can help. First up: @claireholt!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #emilyoster #claireholt #parentingstruggles #parentingtips #latenightpanicgoogle
...

Sun safety is a must for all ages, especially babies! Here are my tips for keeping your littlest ones protected in the sunshine:
☀️ Most importantly, limit their time out in hot weather. (They get hotter than you do!)
☀️ Keep them in the shade as much as possible when you’re out.
☀️ Long-sleeve but lightweight clothing is your friend, especially on the beach, where even in the shade you can get sunlight reflecting off different surfaces.
☀️ If you want to add a little sunscreen on their hands and feet? Go for it! But be mindful as baby skin tends to more prone to irritation.

Comment “Link” for a DM to an article on the data around sun and heat exposure for babies.

#sunsafety #babysunscreen #babyhealth #parentdata #emilyoster

Sun safety is a must for all ages, especially babies! Here are my tips for keeping your littlest ones protected in the sunshine:
☀️ Most importantly, limit their time out in hot weather. (They get hotter than you do!)
☀️ Keep them in the shade as much as possible when you’re out.
☀️ Long-sleeve but lightweight clothing is your friend, especially on the beach, where even in the shade you can get sunlight reflecting off different surfaces.
☀️ If you want to add a little sunscreen on their hands and feet? Go for it! But be mindful as baby skin tends to more prone to irritation.

Comment “Link” for a DM to an article on the data around sun and heat exposure for babies.

#sunsafety #babysunscreen #babyhealth #parentdata #emilyoster
...

I’m calling on you today to share your story. I know that many of you have experienced complications during pregnancy, birth, or postpartum. It’s not something we want to talk about, but it’s important that we do. Not just for awareness, but to help people going through it feel a little less alone.

That’s why I’m asking you to post a story, photo, or reel this week with #MyUnexpectedStory and tag me. I’ll re-share as many as I can to amplify. Let’s fill our feeds with these important stories and lift each other up. Our voices can create change. And your story matters. 💙

#theunexpected #emilyoster #pregnancycomplications #pregnancystory

I’m calling on you today to share your story. I know that many of you have experienced complications during pregnancy, birth, or postpartum. It’s not something we want to talk about, but it’s important that we do. Not just for awareness, but to help people going through it feel a little less alone.

That’s why I’m asking you to post a story, photo, or reel this week with #MyUnexpectedStory and tag me. I’ll re-share as many as I can to amplify. Let’s fill our feeds with these important stories and lift each other up. Our voices can create change. And your story matters. 💙

#theunexpected #emilyoster #pregnancycomplications #pregnancystory
...

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio!

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio! ...

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio!

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio! ...

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio!

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio! ...

Is side sleeping important during pregnancy? Comment “Link” for a DM to an article on whether sleep position affects pregnancy outcomes.

Being pregnant makes you tired, and as time goes by, it gets increasingly hard to get comfortable. You were probably instructed to sleep on your side and not your back, but it turns out that advice is not based on very good data.

We now have much better data on this, and the bulk of the evidence seems to reject the link between sleep position and stillbirth or other negative outcomes. So go ahead and get some sleep however you are most comfortable. 💤

Sources:
📖 #ExpectingBetter pp. 160-163
📈 Robert M. Silver et al., “Prospective Evaluation of Maternal Sleep Position Through 30 Weeks of Gestation and Adverse Pregnancy Outcomes,” Obstetrics and Gynecology 134, no. 4 (2019): 667–76. 

#emilyoster #pregnancy #pregnancytips #sleepingposition #pregnantlife

Is side sleeping important during pregnancy? Comment “Link” for a DM to an article on whether sleep position affects pregnancy outcomes.

Being pregnant makes you tired, and as time goes by, it gets increasingly hard to get comfortable. You were probably instructed to sleep on your side and not your back, but it turns out that advice is not based on very good data.

We now have much better data on this, and the bulk of the evidence seems to reject the link between sleep position and stillbirth or other negative outcomes. So go ahead and get some sleep however you are most comfortable. 💤

Sources:
📖 #ExpectingBetter pp. 160-163
📈 Robert M. Silver et al., “Prospective Evaluation of Maternal Sleep Position Through 30 Weeks of Gestation and Adverse Pregnancy Outcomes,” Obstetrics and Gynecology 134, no. 4 (2019): 667–76.

#emilyoster #pregnancy #pregnancytips #sleepingposition #pregnantlife
...

My new book, “The Unexpected: Navigating Pregnancy During and After Complications” is available for preorder at the link in my bio!

I co-wrote #TheUnexpected with my friend and maternal fetal medicine specialist, Dr. Nathan Fox. The unfortunate reality is that about half of pregnancies include complications such as preeclampsia, miscarriage, preterm birth, and postpartum depression. Because these are things not talked about enough, it can not only be an isolating experience, but it can also make treatment harder to access.

The book lays out the data on recurrence and delves into treatment options shown to lower risk for these conditions in subsequent pregnancies. It also guides you through how to have productive conversations and make shared decisions with your doctor. I hope none of you need this book, but if you do, it’ll be here for you 💛

#pregnancy #pregnancycomplications #pregnancyjourney #preeclampsiaawareness #postpartumjourney #emilyoster

My new book, “The Unexpected: Navigating Pregnancy During and After Complications” is available for preorder at the link in my bio!

I co-wrote #TheUnexpected with my friend and maternal fetal medicine specialist, Dr. Nathan Fox. The unfortunate reality is that about half of pregnancies include complications such as preeclampsia, miscarriage, preterm birth, and postpartum depression. Because these are things not talked about enough, it can not only be an isolating experience, but it can also make treatment harder to access.

The book lays out the data on recurrence and delves into treatment options shown to lower risk for these conditions in subsequent pregnancies. It also guides you through how to have productive conversations and make shared decisions with your doctor. I hope none of you need this book, but if you do, it’ll be here for you 💛

#pregnancy #pregnancycomplications #pregnancyjourney #preeclampsiaawareness #postpartumjourney #emilyoster
...

We are better writers than influencers, I promise. Thanks to our kids for filming our unboxing videos. People make this look way too easy. 

Only two weeks until our book “The Unexpected” is here! Preorder at the link in my bio. 💙

We are better writers than influencers, I promise. Thanks to our kids for filming our unboxing videos. People make this look way too easy.

Only two weeks until our book “The Unexpected” is here! Preorder at the link in my bio. 💙
...