Ok - wow. This story is everywhere. I don't believe these are 'chemical burns' at all. Of course - what is a chemical burn? lol This lady has an allergy, and the reason I think so is because I, too, have a shoe allergy. My feet look just like this if I wear crocs or flip flops. She's making the mistake of thinking that because she has no rubber or latex allergy, it has to be some caustic chemical doing this.
It doesn't. I am not allergic to latex or rubber EITHER. My allergy starts out looking just like a burn.
Here's what most people allergic to shoes have allergies to:
Rubber - the most common,
chromate
p-tertiary-butylphenol-formaldehyde resin (I'm allergic to)
colophony (pine rosin) Here's a severe allergic reaction:
Picture of a severe contact dematitis
See, it looks just like a bad burn? Your skin reacts the same way as if it WERE burned.
That's exactly the way my feet will look if I spend a hour or two in shoes with the resin used in making them.
Sometimes they use that to set the color on shoes, as best I can determine, other times as an epoxy to glue parts together.
Knowing shoe allergies EXIST is good information to know - like I said, even some GPs have not heard of allergies to shoes, and they are quite rare, but they happen, sometimes out of nowhere. If your feet itch or look red after being in shoes - take them off, and get them washed. If they start looking burnt or blistered, start with the cortizone and benadryl. These types of allergies can often appear where there was none before. She needs a patch test for the chemicals above. I've written and told her that. There's no way I'd expect Wal-mart to pay for my doctor visits for an allergic reaction I had to something.
However, it would be very nice to know what shoes I want to buy are made of. No one will tell you though. | 
