When i was a teenager i had itchy scalp and no dandruff. My doctor prescribed a black shampoo. The first shampoo was cool on my scalp. The doctor called and asked what the effect of the shampoo was. We said it was cool. He prescribed a second shampoo of a higher dose. This shampoo burned cool on my hands and scalp. My scalp had a layer of dead skin on it. My mother flaked the dead skin away with a comb. The itching stopped. My mother washed my head and hands for a few times until the bottle was gone. It took 3-5 days. That was 20 years ago. I think my mother has this bug. She scratches her head constantly. She has no dandruff. Do you know what this bug could be. We have tried over the counter dandruff shampoo with relief for a few hours. I am thinking it is the same bug, which she has picked up in this house. Do you know what the shampoo was for.