A chemical burn is a special type of burn injury, caused by a chemical agent. It occurs when living tissue is exposed to such a corrosive chemical compound, most commonly a base or an acid. These burns don't need a source of heat and can be extremely painful, as they evolve very quickly.
Symptoms of chemical burns depend on the causing agent. However, most of them are characterized by a superficial or profound destruction of the tissue and a sensation of intense heat or pain. Some tissues are more vulnerable than others -- for example, even mildly corrosive substances can cause damage one's eyes while not causing anything but discomfort on the hands.
If the injury occurs internally, it can also be associated with poisoning, which renders this type of burns more difficult to treat.
First aid and treatment
First aid should consist of neutralizing the chemical agent if possible. This should be performed with great care, because some neutralizing reactions are exotermal or produce poisonous substances, causing even more damage. Irrigating the affected area with cool, clean water is also an option, but it should also be handled with care because some substances react violently with water and can cause further damage.
Treatment involves removing the agent and, in most cases, performing a high-density water shower. Surgical intervention may be required, especially if the burns are deep and require skin grafting.