Why Are My Mosquito Bites Only Behind My Knee?

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Discussion Overview

The discussion centers around the cause of multiple insect bites experienced by a participant, specifically located behind the knee. Participants explore various possibilities including mosquitoes, fleas, spiders, and other insects, as well as potential skin reactions. The conversation includes personal anecdotes and observations related to insect bites and their characteristics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant reports multiple bites in a small area behind the knee, questioning how mosquitoes could have reached that spot while ignoring other exposed skin.
  • Another participant shares a similar experience in Japan, noting a different skin reaction and expressing confusion about the source of the bites.
  • Some participants suggest fleas as a possible cause, noting their tendency to bite multiple times in the same area.
  • Others propose that spider bites could be responsible, particularly in creases where skin is thinner.
  • There are mentions of dog mites and chiggers as potential culprits, with some participants recalling past experiences with similar bites.
  • A few participants discuss the possibility of heat bumps or cholinergic urticaria, which can resemble insect bites.
  • Some express uncertainty about the identification of the bites, with differing opinions on their characteristics and origins.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the cause of the bites, with multiple competing views and hypotheses presented throughout the discussion.

Contextual Notes

Some participants reference previous similar experiences, suggesting a potential seasonal correlation, but there is no verification of the specific cause of the current bites. The discussion includes various assumptions about the nature of the bites and the insects involved.

DaveC426913
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Sunday night I sat outside for three hours. I was wearing long pants and a sweatshirt and there was a mosquito candle on the table in front of me. There are confirmed mosquitos still in our yard, though I did not swat any away that night.

A few hours after coming in, I found I had about 9 mosquito bites, all of them in the crease of the back of my left knee. All within a two inch area. I got no other bites anywhere on me.

If they are indeed mosquito bites, they would have had to ignore all the exposed skin on my head/neck/face/throat and hands, and instead fly up my one pant leg, land at my knee and bite me nine times.

I'm trying to find alternate cuplrits to explain the bites. Spiders or ants, on the edge of the chair, maybe biting through my pants? No.

I thought maybe chiggers, that tend to bite many times near creases and stuff.

But these are exactly like mosquito bites (though big, tightly grouped and quite itchy).

I have a pic but that won't tell you much. They look and feel like mosquito bites.

Ideas?
 
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I had the same situation in Japan, I was covered in DEET and was wearing long pants. Still some bug managed to bite me just below the knee in the morning hours. It didn't appear to be mosquito bites, because the kind of skin reaction was different than usual. I was, and still am, puzzled by the origin.

I hate mosquitos. The fall has already set in two months ago, but I still find mosquitos in my room every night. All I need to do is wake up (usually around 3 am) and find a mosquito camping out above my pillow, which I then catch in a glass and get rid of. The same ritual every night. Today I was stalked by another mosquito, but now in the train. It didn't want to leave my side, but I was fortunate to not get bitten. If you don't want to bitten by bugs, you just need to hang out with me: I'm a better bait.
 
Fleas, maybe?

I think I'll go with spider, though. One may have crawled up your pants...*shiver*.

Oh great, now I have the heebie-jeebies.
 
I often get bitten by fleas as well (in public places, I don't own pets) They are very easy to recognize though, I always catch them while biting. It is a good candidate for Dave though, fleas do like to bite in the same spot multiple times.
 
Hmm. Fleas.

Well, the grouping fits.

Though flea bites are usually tiny and red, aren't they?
 

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Could be the mites that are responsible for sarcoptic mange in dogs. VERY itchy bumps.
 
Looks like flea bites to me, they usually become red after a day. The swelling is quite strong, it could have been a different kind that you have a stronger reaction to than usual?
 
How far are you from the bed bug plague that's taking over NY Dave?
 
Dave, dog mites love to bite in creases where the skin is very thin. You won't notice them while biting - only afterward when your immune system kicks in.
 
  • #10
turbo-1 said:
Dave, dog mites love to bite in creases where the skin is very thin. You won't notice them while biting - only afterward when your immune system kicks in.

Dog mite gives man nine bites!
 
  • #11
I think it is more likely that they were caused by something that was already in your pants before you put them on, rather than by something that somehow made its way up your pants to that specific spot on/behind your knee.
 
  • #12
Dembadon said:
I think it is more likely that they were caused by something that was already in your pants before you put them on, rather than by something that somehow made its way up your pants to that specific spot on/behind your knee.
We've had an outbreak of spiders here. They've sprayed all around the outside of the apartments and around the windows, so all of the spiders have come inside for safety. I regularly turn my clothes inside out and shake and thoroughly check my shoes before getting dressed now. I've never seen so many different spiders.

I think it's a flea or a spider Dave.
 
  • #13
In https://www.physicsforums.com/showthread.php?t=262090" thread, which was created around the same time of the year (fall) about two years ago, you had a similar episode. Chemisttree thought they might be chiggers (post #15). Could this be a repeat occurrence? Were you able to verify if they were chiggers or not?
 
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  • #14
The spider bites I have always seen had a crater-like center. I don't know if that is always the case, but I have seen a fair number**.

The bites sure look like mosquitos to me. I have never seen human flea bites, so I can't say much there.


**when we were kids my brother had a monster wolf spider snacking on him for s few nights until we lured the bastard out and killed it. He probably had 50 bites on him in the end.
 
  • #15
Norman said:
The spider bites I have always seen had a crater-like center. I don't know if that is always the case, but I have seen a fair number**.

The bites sure look like mosquitos to me. I have never seen human flea bites, so I can't say much there.


**when we were kids my brother had a monster wolf spider snacking on him for s few nights until we lured the bastard out and killed it. He probably had 50 bites on him in the end.

Ouch, that's a bad place to get even one bite.
 
  • #16
Dembadon said:
In https://www.physicsforums.com/showthread.php?t=262090" thread, which was created around the same time of the year (fall) about two years ago, you had a similar episode. Chemisttree thought they might be chiggers (post #15). Could this be a repeat occurrence? Were you able to verify if they were chiggers or not?

Wow, I'm impressed! You have a memory like a steel trap!
 
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  • #17
Dembadon said:
In https://www.physicsforums.com/showthread.php?t=262090" thread, which was created around the same time of the year (fall) about two years ago, you had a similar episode. Chemisttree thought they might be chiggers (post #15). Could this be a repeat occurrence? Were you able to verify if they were chiggers or not?
I had forgotten about his attack last year.
 
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  • #18
lisab said:
Wow, I'm impressed! You have a memory like a steel trap!

Actually, I noticed it in the 'similar threads' area at the bottom of this thread. I was even more surprised when I saw the seasonal correlation.

I wish my memory was that good!
 
  • #19
Evo said:
How far are you from the bed bug plague that's taking over NY Dave?
Don't think so.

Dembadon said:
I think it is more likely that they were caused by something that was already in your pants before you put them on, rather than by something that somehow made its way up your pants to that specific spot on/behind your knee.
Well, then they waited around for 12 hours before biting.


Dembadon said:
In https://www.physicsforums.com/showthread.php?t=262090" thread, which was created around the same time of the year (fall) about two years ago, you had a similar episode. Chemisttree thought they might be chiggers (post #15). Could this be a repeat occurrence? Were you able to verify if they were chiggers or not?
Wow. Even I didn't remember that. Two years ago next week.


I have remembered that, an hour before going in, I chased a spider out of the tent over my head and it dropped on the ground. Shortly after that, it zoomed across my belly while I was stting and I had to shake it off. So, spider on the ground right at my feet, hanging from me by silk...
 
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  • #21
jarednjames said:
http://www.patient.co.uk/health/Physical-Urticarias.htm

Look for the section: Cholinergic urticaria

Heat bumps? Look like bites and are really itchy. Look exactly like the photo you gave, I get them sometimes.

Home remedy (apparently, I just let them go):
http://www.ehow.co.uk/way_5591552_home-remedy-heat-bumps.html

Well I get heat rashes; I don't think this is from heat (it was quite chilly out - did I mention I was actually wearing something that had long sleeves? Before December?)
 
  • #22
DaveC426913 said:
Well I get heat rashes; I don't think this is from heat (it was quite chilly out - did I mention I was actually wearing something that had long sleeves? Before December?)

Yeah but sweat can cause it. It is under the knee after all.

But sometimes they appear rather randomly on my skin. Itch for about ten minutes and then disappear.
 
  • #23
jarednjames said:
Yeah but sweat can cause it. It is under the knee after all.

But sometimes they appear rather randomly on my skin.
Yeah. I'm pretty familiar with how my bod reacts to heat.

jarednjames said:
Itch for about ten minutes and then disappear.


These have been nasty, nasty itchy for two days. Like, enough for me to actually actually apply stuff on them (and I hate applying stuff). I apply it about every four hours.
 
  • #24
DaveC426913 said:
These have been nasty, nasty itchy for two days. Like, enough for me to actually actually apply stuff on them (and I hate applying stuff). I apply it about every four hours.

Sounds nasty.
 
  • #25
DaveC426913 said:
Dembadon said:
I think it is more likely that they were caused by something that was already in your pants before you put them on, rather than by something that somehow made its way up your pants to that specific spot on/behind your knee.

Well, then they waited around for 12 hours before biting.

Another unlikely scenario. I made the poor assumption that you put on the pants just before going outside.

DaveC426913 said:
A few hours after coming in ...


The following quote is from http://www.medicinenet.com/chiggers_bites/page2.htm" (don't know how reliable this website is).
MedicineNet said:
A chigger bite itself is not noticeable. After the chigger has begun to inject digestive enzymes into the skin (usually after about 1-3 hours), symptoms typically begin.

Hardly a case-closing discovery, but it fits the time-frame nonetheless.

How cold was it? The site claims that "[c]higgers do not bite at colder temperatures (below 60 F or 15.5 C)." I'd guess it was colder than that if you were wearing pants and a sweatshirt, but people's comfort-level thresholds for air temperatures are different, so I figured I'd ask. Another observation that could rule out chiggers is that you were appropriately dressed, as the site suggests "[l]ong pants and long-sleeved shirts as well as thick socks and high shoes or boots can help prevent infestation. Pants legs should be tucked into shoes or boots if possible."

Perhaps it was the spider. Can you describe your arachnid admirer?
 
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  • #26
lisab said:
Ouch, that's a bad place to get even one bite.

:smile: :smile:
 
  • #27
Dembadon said:
How cold was it? The site claims that "[c]higgers do not bite at colder temperatures (below 60 F or 15.5 C)." I'd guess it was colder than that if you were wearing pants and a sweatshirt, but people's comfort-level thresholds for air temperatures are different, so I figured I'd ask.
It was probly about 15C. Simply sitting for 2-3 hours can require a long-sleeve.

Dembadon said:
Another observation that could rule out chiggers is that you were appropriately dressed, as the site suggests "[l]ong pants and long-sleeved shirts as well as thick socks and high shoes or boots can help prevent infestation. Pants legs should be tucked into shoes or boots if possible."
No, just normal late season* clothes. (*which means actually wearing socks)
Dembadon said:
Perhaps it was the spider. Can you describe your arachnid admirer?
Common garden spider. Get em around here by the buttload.
 
  • #28
DaveC426913 said:
Common garden spider. Get em around here by the buttload.
That's NOT where you're supposed to keep them, you know.
 
  • #29
Dave,

Without knowing exactly what got to you, you have to admit one thing, your immune system had an abnormally aggressive reaction (and possibly time delayed reaction) to it, right ? Based on that information, assuming you have never had welts like this in the past (and knew where they came from), would be be reasonable to suggest that whatever bit you multiple times was "brand new to you immune system" ? With that many welts, did you feel the first one ? I bet once your immune system went postal, you did. Really strange that you didn't feel them as they happened. From the picture you posted, it looks like there is some kind of delayed reaction going on as well. Sorry I couldn't pin this down for you. They, the welts that is, didn't burst open and weep, did they ?

Rhody...
 
  • #30
rhody said:
Dave,

Without knowing exactly what got to you, you have to admit one thing, your immune system had an abnormally aggressive reaction (and possibly time delayed reaction) to it, right ? Based on that information, assuming you have never had welts like this in the past (and knew where they came from), would be be reasonable to suggest that whatever bit you multiple times was "brand new to you immune system" ? With that many welts, did you feel the first one ? I bet once your immune system went postal, you did. Really strange that you didn't feel them as they happened. From the picture you posted, it looks like there is some kind of delayed reaction going on as well. Sorry I couldn't pin this down for you. They, the welts that is, didn't burst open and weep, did they ?

Rhody...

Are you sure you're not overthinking it?

Sure, they're itchy as heck, but I think that's because there's so many. The nerves are being terrorized. And it's in a spot that is sensitive and continually stimulated.

But when all is said and done, they're exactly like mosquito bites.

The only thing uncharacteristic is their location and grouping density (sheer number in a small area), which is very unlike mosquitoes.
 

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