What Causes Soreness Of Skin After Eating Food With High Sugar Content?

I get very sore skin after eating high sugar foods, sometimes even just white bread. It feels like my skin on my neck, shoulders and back is bruised and that my glands are swollen. I've noticed it happens if I eat quite a lot. I'm not sure what it is. Any thoughts? When eating normally I don't usually have a problem, its just after a big meal, special occasion or 'pig out'.