Welcome to HCM.
Itchy scaly patches usually denote fungal infection
called taenia infection
. This infection can be easily treated by application of antifungal cream over the affected area for two weeks. If does not reduce get a dermatologist
opinion for the lesion. Skin discoloration also occurs in a condition called as vitiligo
. This is usually caused by minor trauma and occurs only in people who are predisposed to this condition. I suggest you get that condition also ruled out by a dermatologist.