Instead, nearly 90% of lightning victims survive. Less than one third show any external burns at all, probably because the vast majority of lightning injuries are actually indirect. In addition, there is no evidence to support internal burns without external ones. The burns that occur are almost universally secondary burns, not primary lightning burns.
Lightning is primarily a nervous system injury, involving injury to any or all of the three divisions of the nervous system. Since nerve tissue does not heal well, survivors may have permanent damage or disability including chronic pain due to peripheral injury or thought processing and attention problems due to brain injury.
There is no known medical therapy to stop the cascade of injury once it is set in motion with the initial insult. Thus, it is far better to prevent the injury than to treat the survivors.