Have a crater/ant hill looking wound that may or may not be a chemical burn. what should i do?

What's the cause?: When our bodies sustain an injury, the response is inflammation (red, hot, tender swelling). This is the body increasing blood flow and bringing healing factors to the area and the veins expand to carry bad stuff away. While this is generally how things heal, the question is what caused the wound. Bedsores are treated different than vein ulcers, neuropathic ulcers, etc. We need the cause.