My scalp was itching like crazy and got sores from scratching so i washed my scalp with ivory bar soap and it stopped. why is that? washing stops it.

Itching: If you are sweating a lot the scalp can get very irritated and inflamed. But sometimes the scalp get inflamed from just being dry. Medicated shampoos help (like neutrogena t gel or Nizoral (ketoconazole) which are over the counter). If this does not help, i suggest being evaluated for dermatitis along the scalp which is a common and treatable condition. Hope that helps.