That is not the only dye/foodstuff that can change the colour of skin or nails:
Wholesome baby food website discusses the question: Why is my baby orange.
|Image: keeleymorris on Twitter|
Carotenemia is a medical term for a condition that causes the skin to turn orange-ish due to increased blood carotene levels. In the vast majority of cases seen, it is associated with large consumption of carotene in the diet; as in too many carrots or sweet potatoes. Read more at http://wholesomebabyfood.momtastic.com/orangebaby.htm#1kHfjLYwFgte6T66.99
more at Wikipedia
we see this a lot in kids, and the way you can tell it's not jaundice is that their eyes are not yellow. The treatment is to reassure the parents.
I've only seen it once in an adult: It she admitted that she had a craving for carrots.
People who are anemic often have similar cravings: although ice eating and starch/clay eating are more common. (The technical term for this is pica).
I tested her, and sure enough, she was anemic and low in iron.
but carrots are not the only food that can cause problems: tomatoes can do it also, from the lycopene in them.
argyria is from silver in the skin (benign). One of the problems for "preppers" who use AgNO3 for medical problems.
and Iron overload (from a genetic defect, hemochromatosis or from being given too much iron for severe anemias,) can also discolor the skin.
It's not hemochromatosis per se, but there is a well known problem of dark black skin in Bantus in Africa.
We saw a lot of very dark skin in our heavy native-beer drinkers in Africa: it is because the local beer is brewed in iron kettles, but also because some people carry a gene that makes them vulnerable to the condition.
Dietary iron overload is the consumption of large amount of home-brewed beer with high amount of iron content in it. Preparing beer in iron pots or drums results in high iron content. The iron content in home-brewed beer is around 46–82 mg/l compared to 0.5 mg/l in commercial beer
we didn't treat it as such (often these patients also had cirrhosis from alcohol, and/or viatmin B deficiency, so mainly we would feed them up and tell them to stop drinking).
The Wikipedia article also suggests this might be behind the high rate of liver cancer in Africa, but I have also read that mold in certain foods might be another reason for this, or maybe Hepatitis C.
finally, there was a book of medical mysteries that included a story about 11 blue men.
usually when patients are blue, it is due to lack of oxygen from heart or lung problems.
For example: we docs separate lung disease in smokers into pink puffers (pure emphyesema) and blue bloaters (Chronic Bronchitis...Bloaters is British slang for a person who coughs up lots of phelgm). Because the mucus causes CO2 retention, they tend to have a high CO2 level and tend to be a bit cyanotic.(blue)
But the classic story "11 Blue Men", this was due someone accidentally putting sodium nitrate into salt shaker.
Full story HERE
quite a few medicines can cause methhemoglobinemia, but most of these medicines are used in doses too small to cause problems unless you overdose, or unless have a genetic problem. this long medical article discusses the problem.
and then there is a rare congenital form of methhemoglobinemia that runs in families... one example is the Blue Fugates of Kentucky.
------a shorter version is on my FKCLINIC blog.