How do you get emphantigo?

What is emphantigo?

Not Sure how its spelled exactly, but when I was younger I went camping outside. It was very hot. We of course went to the bathroom outside, which left me with yucky hands, and it was so hot Id be scratching my head. After a short amount of time I developed these big, blistery sores all over my head. Its hard to explain them. I remember they were infected. If I scratched at them it hurt badly and they were oozy and scabby. It made me scream to put my head in water ( like to wash my hair ) to put my head in front of a fan was sooo unbelievably painful, just the air from the fan. Im sure cases can be different. The doctor confirmed it was emphantigo and that was how it was for me.