Think you may be allergic to coconut? It's used in most skin care products.....and toothpaste. So if you're gagging at night and have itchy skin, it could be coconut derivatives. I also have put a link to a list of all (or at least most) cosmetic and skin care ingredients.
Like Becky in the first link below, I have discovered that I appear to be allergic to coconut and it's derivatives used in food and personal care products, which are many and I think, overwhelming (see list in Becky's post). Some of the alternatives like palm oil are just as bad, together with soya used in many manufactured foods from bread to luxury chocolate.
In my case, I have not been able to eat coconut for many years, but recently I developed intense itching on my scalp, easing now I have given up using shampoo, using olive soap instead. I'm using it on my body and face as well. I also found a toothpaste free of coconut derivatives and my breathing and throat obstruction is slowly easing.
This is Becky's Blogger post: http://coconutallergy.blogspot.co.uk/
This is a forum I found with useful info: http://www.latitudes.org/forums/index.php?showtopic=2501
I found a list of seemingly all cosmetic ingredients for good or bad: http://www.paulaschoice.com/cosmetic-ingredient-dictionary/
Many of these ingredients do not have coco- or coca- in the name, like sodium laurel sulfate/sulphate (made from coconut and/or palm oil). Please note that cocoa in chocolate is not a problem.
Something else to think about: many of these products come from GM crops and may be grown in areas where rainforests are being destroyed to make space for them, particularly palm oil.
As I get more info, I will post it on here, but so far, after eliminating as much coconut as I can find, I am improving.