Hi I have a dark line that has appeared on the knuckle skin of my big toe - it is brownish in colour and slightly raised - a bit like a mole starting. My other big toe looks as if it is starting to do the same. I have a histamine problem where my own body is attacking itself and I take large amounts of histamine daily. I also take steroids for asthma and allergies. I take tegretol regard for bipolar disorder as well. I wear flip flops all summer so my toes are always exposed and warm ugg boots in winter. I crave sugar and have read so many bits of advise on the Internet am really confused.