Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: kdlynn on 27/05/2007 04:50:06

Title: strange green dot on my knee
Post by: kdlynn on 27/05/2007 04:50:06

when i was six i was running late for school. i tried to close the snap on my back pack while hurrying up the hill to school. it caught the skin on my knee and pinched it pretty hard. ever since then, i have had a little dark green dot on my knee. my doctor says it's odd, but it has not changed or moved or done anything strange, so he is not worried about it. does anyone know what it really is though? it looks like someone took a marker and put it there.

Title: strange green dot on my knee
Post by: kdlynn on 27/05/2007 04:51:47

it's about the size of a pencil dot or a very thin marker dot, but it's definitely green

Title: strange green dot on my knee
Post by: another_someone on 27/05/2007 09:20:24

Green is a strange colour for the human body.  My own first thoughts would either be a small slither of metal under the skin, or some fungal infection.

In either case, I would have been happier if it was not there, but I suppose if it has not got worse, then it is not appearing to be causing harm.

Then again, maybe someone has a more imaginative answer than mine as to what might cause a green colouration.

Title: strange green dot on my knee
Post by: _Stefan_ on 27/05/2007 11:11:15

Photos would be helpful :)

Title: strange green dot on my knee
Post by: rosy on 27/05/2007 13:01:00

Could be something embedded under the skin? I have a grey mark under the skin of my right palm from stabbing the writing end of my pencil into myself about 10 years ago... it's just graphite. It's not very surprising that it's pretty persistant as I think sailors used to use charcoal to push under the skin with needles to form tattoos. Don't know whether that's likely, or what the green colour would be...

Title: strange green dot on my knee
Post by: kdlynn on 27/05/2007 15:23:52

i tried to take a photo but i can't focus on it very well. my mom has a better camera. i'll try hers later today. thanks guys

Title: strange green dot on my knee
Post by: iko on 27/05/2007 18:31:24

Hi kdlynn,

it sounds like a typical TAT:
Tiny Accidental Tattoo!
(I just invented a disease!)
Some tiny particles, may be blue-black
dusty bits entered the skin and have
been fixed and engulfed by macrophages.
Just like in a tattoo.
Take care

ikod

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhealth.yahoo.com%2Fmedia%2Fmayoclinic%2Fimages%2Fslideshow%2Fc22_rtmark.jpg&hash=a436abc38a92f50ed571969857f39802)
http://health.yahoo.com/media/mayoclinic/images/slideshow/c22_rtmark.jpg

more about tiny tiny tattoos:   http://health.yahoo.com/topic/cancer/treatment/article/mayoclinic/491544AC-2A5D-9994-EBE274EA4E6F431B

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Title: strange green dot on my knee
Post by: chris on 28/05/2007 17:46:40

Were you wearing trousers at the time of the original accident? And if so, what colour were they? Either way, what colour was the rucksack and the clasp on the rucksack?

Chris

Title: strange green dot on my knee
Post by: kdlynn on 28/05/2007 17:51:15

i was wearing a skirt. it was pink and white striped (it was the eighties, ok? lol) my bag was purple with tweety bird on it and the clasp was silver. i'll never forget that bag because of this incident

Title: strange green dot on my knee
Post by: benep on 28/05/2007 17:53:08

well ye some kind of green substance has been stabbed into your knee by teh sound of it

Title: strange green dot on my knee
Post by: paul.fr on 29/05/2007 21:04:59

I would suggest that the buckle was made from (base metal)or coated with copper.

Title: strange green dot on my knee
Post by: iko on 30/05/2007 00:12:08

Quote from: paul.fr on 29/05/2007 21:04:59

I would suggest that the buckle was made from (base metal)or coated with copper.

Good idea:
copper sulphate is bright green

Title: strange green dot on my knee
Post by: chris on 31/05/2007 12:51:59

I think this is a traumatic tattoo. It happens sometimes when tiny particles are forced into the dermis by an injury. If the particles are not degradable, just like tattoo pigments, they will be picked up by local phagocytes (cells that eat things) and immobilised. I think this is likely to have happened here, although the source material for the tattoo isn't obvious. I presume that the spot doesn't blanche (disappear) when you apply pressure to the area?

Chris

Title: strange green dot on my knee
Post by: kdlynn on 31/05/2007 17:01:55

no it doesn't disappear. hmmm... and my mother always told me i wasn't allowed to have a tattoo. lol

Title: strange green dot on my knee
Post by: Xule on 01/06/2007 18:19:02

maybe that was a covert means of planting an electronic tag under your skin...
they're watching you!!! [:0] [:o)]

Title: strange green dot on my knee
Post by: kdlynn on 02/06/2007 03:56:20

that's just wrong... they shouldn't use purple tweety bird book bags for first graders... lol