一粒粒既肉粒白色野,好痕癢. It seems your skin are allergy in something, this is the reaction maybe your underpant, the soap that you used. Yo have to used 100% cotton made underpant, used neutralized soap or liquid soap.
For the time being, you can buy the cream called Sunnicomb cream that you buy in normal drug store. It is very effective skin cream. Good Luck.