Thread by @RGottliebSmith

1/
The only good thing to come of finding this on my leg last week: I learned enough to write a #tweetorial about it

A 🧵/twitter PSA about what to do if a tick comes for you – & what neuro presentations you can see w/ tick-borne illnesses

#MedTwitter #NeuroTwitter #IDTwitter

2/
After time outside in a non-wooded area, I found this on my leg. I didn’t realize what it was, so I grabbed it & flung it off... only to then find a very active, crawling tick on my counter. 😱

So after freaking out for a moment (or 2), I had to figure out what to do with it.

3/
Memories from med school flashed into my head of what you’re SUPPOSED to do:

1⃣ Remove tick w/ tweezers
2⃣ Grab close to skin & pull tick off without twisting so it doesn’t break apart
3⃣ Disinfect

Since I had already accidentally messed up 1⃣ & 2⃣, I started w/ 3⃣

4/
After the 🪲 was safely in a plastic bag, the next❓ was – do I need prophylactic doxycycline for Lyme disease (borreliosis)?

To answer this, I needed to determine the tick species. Which, at least for me, was much harder than it seemed!

cdc.gov/ticks/tickborn…

5/
So help me out. #MedTwitter, which type of tick do you think it was?

6/
The size (4-5mm) seemed large for a deer tick, but I didn't see markings on its back that you’re supposed to see w/ dog ticks.

(Hopefully #MedTwitter will clarify - & I realized later that recent guidelines recommend sending the tick for species ID: pubmed.ncbi.nlm.nih.gov/33257476/)

7/
So when do you think about doxycycline prophylaxis?

1⃣ It’s a deer tick
2⃣ Estimated time on = 36+ hrs
3⃣ Can start within 72 hrs
4⃣ No contraindication
5⃣ Area of high Lyme prevalence

cdc.gov/lyme/resources…

8/
Even if it was a deer tick, because the estimated time on was <36 hours for me, & Michigan is an area of low Lyme prevalence, I didn’t meet the criteria… but I will be watching for any symptoms. (No rash so far!)

cdc.gov/lyme/resources…

9/
Which brings us to the next part: what tick-borne illnesses do we see?

Here are the more common ones in US: cdc.gov/ticks/tickborn…

We’ll focus mostly on ones w/ possible neuro involvement

Let’s start w/ the one most think of (& that you consider prophylaxis for): Lyme

10/
Lyme disease in US is caused by spirochete Borrelia burgdorferi & carried by deer tick

3 phases (can treat to prevent progression):
1⃣ Early localized (“bull’s eye” rash = erythema migrans): up to 30 days after bite
2⃣ Early disseminated: ~3-12 wks after
3⃣ Late

11/
Potential neurologic manifestations of Lyme:
🪲 Meningitis
🪲 Cranial nerve palsies (especially facial nerve)
🪲 Radiculopathy
🪲 Peripheral neuropathy (mononeuritis multiplex)
🪲 Encephalitis (rare)

👇 facial palsy 📷s from pubmed.ncbi.nlm.nih.gov/31021433/

12/
Next, let’s talk about babesiosis

Babesiosis in the US is typically caused by Babesia microti & also spread by the deer tick

Headache & fatigue are common (along with fevers, chills, muscles aches & hemolytic anemia) but other specific neurologic manifestations are not

13/
Anaplasmosis & ehrlichiosis are both caused by bacteria in Anaplasmataceae family

🪲 Both can be spread by deer ticks, but ehrlichiosis more often by lone star
🪲 Both: fever, headache, fatigue, GI symptoms, rash (less common)
🪲 Ehrlichiosis: also meningoencephalitis

14/
Rocky Mountain Spotted Fever is caused by Rickettsia rickettsii, and spread by dog ticks & wood ticks (NOT the deer tick - change up!)

🪲 Classic signs: fever, headache, and rash
🪲 Can see encephalitis and seizures

15/
Rare & due to a virus as opposed to a bacterium, but also carried by the deer tick: Powassan virus

🪲 Can cause a severe meningoencephalitis
🪲 Increasing in recent years (I learned about this in residency)

16/
& not due to a bacterium or virus, but ticks can produce a toxin ➡️ tick paralysis

🪲 Many species - in US, primarily Rocky Mountain wood tick & American dog tick
🪲 Often ascending paralysis, like in Guillain-Barré syndrome

⚠️ ✔️skin closely in anyone w/ acute paralysis!

17/
So wish me luck!

💡 Reassuringly, most tick bites don't result in disease
💡 If you find a tick: use tweezers ➡️ disinfect ➡️ ✔️ if need Lyme prophylaxis
💡 Most tick-borne illnesses caused by bacteria, but virus- & toxin-related occur, too
💡 Don’t forget to ✔️ skin for 🪲!