Skip to main content

Lyme Disease

Key Lyme Points

As we are entering the outdoors/warm season, I start getting a lot of frantic calls and emails about limes, probably because of all the limeade floating around out there.  Well don't worry because in a pinch,  grapefruit or lemons are a good substitu...

Oh sorry, I meant I get a lot of frantic calls and emails about LYME disease.  There is a ton of information and misinformation out there about Lyme disease so I'm going to try to go through it bullet point style and just hit the salient features.

- Let's start with ticks.  The most common tick around here is the wetern black-legged tick (Ixodes pacificus) and they are active pretty much all year long.  The adults are most active from around the first rain of the year till May and the nymphs (babies) are most active from January till the end of summer.  But this is a little outdated data which will probably change as the climate continues to, so let's just assume ticks are always around.

- Most people call me after they removed a tick noting some redness and swelling and pain.  This is the normal reaction that happens after basically any insect bite and has nothing to do with Lyme disease.  This should be treated the same way as a mosquito bite - don't itch it, don't pick at it, clean it with soap and water, and use ice or a topical anti-itch cream or ointment as needed.

- Lyme disease is caused by Borrelia Burgdorferi, which is a type of bacteria called a spirochete.  This bacteria is spread from the ticks to reservoir animals like deer and mice, which can then house the bacteria until it's transmitted to other ticks feeding on it.

- We really don't have much Lyme disease in California, especially compared to the East Coast.  96% of cases of Lyme disease in the country are along the Eastern seaboard as well as Wisconsin and Minnesota.  The number of ticks with the Borrelia bacteria is also much much higher over there.

- The highest incidence of lyme disease in California seems to be May through July, meaning that generally the disease is spread by the nymphal ticks, which are smaller and harder to spot than the adults.

- Your change of getting lyme disease from a tick is generally pretty low.  First, the incidence of borrelia in our tick population is at least 10 times lower than on the east coast/Wisconsin where most lyme disease is, so you just don't have as good a chance of running into a tick that has it.  Second, they need to have been feeding for at least 36-48 hours and be visibly engorged to have had the chance to transmit the disease, and most people find them before that.  On the East coast, it's been reported that you probably have about a 2% chance of getting Lyme disease from a tick bite.

- The best way to prevent a tick bite is to keep from getting a tick in the first place, meaning covering up all your exposed skin when you're going to be out in the woods and tucking your pants into your socks.  After you come back from being outside, looking over your body for ticks is a great idea - the lower legs and lower abdomen are big places people find them as well as the head and neck.  If you do find one, forget everything you've heard about ways to try to get rid of them and instead, grab them with some tweezers (or fingers if you have no tweezers) as close to the head as possible and pull perpendicular to your skin.  You can find out much more about removing the tick here as well as where to take it for testing to find out if it was infected with Lyme (for San Mateo county).  The County health department also has a good page on Lyme Disease here

- For people who have definitely found an engorged Ixodes tick or think it's been there for greater than 36 hours, our infectious disease specialists think it is reasonable to give a one-time prophylactic dose of doxycycline if it can be given within 72 hours.  This has been shown to be effective in reducing the rate of transmission of Lyme disease by about 2% on the east coast, so it's efficacy in California is unknown but probably 2% or less.  There are small but real potential downsides to antibiotics as well, even in low doses, so I generally don't lean towards using them unless there's a convincing reason given the low chance of benefit.

- If you are unlucky enough to get Lyme, the first sign is usually a red lesion that looks like a target, which pops up on average about a week after being bit by the tick but can happen up to 30 days later.  About 4 out of 5 people who get Lyme disease have this (it's called erythema migrans).  We can do lab tests to check to see if you have it too but they're not usually positive for several weeks after you've gotten it.

Much much more on this here if you're interested

The UC Integrated Pest Management Program
Seasonal patterns (or lack thereof) of Lyme disease in California

Labels:

Popular posts from this blog

NSAIDs

Advil and Motrin are ibuprofen, then you have Aleve (naproxen).  Those are the over-the-counter ones.  Prescriptions are Mobic (meloxicam), nabumetone, indomethacin, Toradol (ketorolac), diclofenac, Lodine, and the list goes on.  All of these medications are in a class called non-steroidal anti-inflammatory drugs (NSAIDs). I'm giving you this list because there is mounting evidence that these medications a) don't work as well as we'd thought and b) have some very serious long term side effects we're finding out more about. NSAID's act by reducing the amount of prostaglandins you make in order to reduce inflammation.  However, prostaglandins have a ton of other effects and are involved in the maintenance of just about AIDs and also stronger if they are taken every day and/or around-the-clock.  every other organ system that you have.  The effect is stronger with higher doses of NS NSAID's work best and are best indicated for times when something is r...
Read more

Kidney Stones

I've written about this previously , but it's often hard to explain to people what a 10 is on the "1-10" pain scale if they haven't been in that spot before.  For women who have had children, they generally know what a 10 is, but for men it's a little harder.  When I was a medical student on my psychiatry rotation, we had a patient calmly sitting there saying his pain level was at a 10 and our resident, who was an ex-military sniper with a large skull tattoo on his forearm and a crosshair through the eye, calmly leaned forward and asked, "so if I lit you on fire and ran you over with my truck, you could not be in more pain than you are now, correct?"  The patient changed his answer. Getting to the point, a kidney stone is about the close I can come to describing a 10/10 pain to people who haven't gone through childbirth.  The fundamental issue is similar - your body is trying to move a big solid thing through an opening that was not really desig...
Read more

Pain

Sorry to be a pain I would say about 90% of the comments I hear from people about their pain threshold is that they think they have a high pain tolerance.  Which is statistically impossible unless I just attract people who have a high pain tolerance. We traditionally ask people to rate their pain on a 1-10/10 scale and while we hear a lot of 9's and 10's, I would say that, having been present for a number of them, a 10/10 would be giving birth to a first child.  For those who haven't experienced that, my old psychiatry resident described it as "so if I lit you on fire and ran you over with my truck, you would not be in any more pain than you are now" (he was also a former Marine sniper which might explain that). But this is pretty pervasive throughout the medical system and got me wondering as to how people's understanding of what their pain threshold was matched up to what it really was.  Fortunately, there were researchers who had a yen to poke peopl...
Read more