thanks for using healthcare magic.
i will be glad to be of assistance.
the dark pigment is from constant scratching as you mentioned.
it will be better to take an antihistaminic like loratidine
10 mg once a day to control the itching.
also please try consciously not to scratch. also you will need to use a steroid
cream like mometasone
furoate once a day for a week to control the inflammtion there.
after that for dark pigment you can use glycolic acid
6% cream once a t night daily. that will reduce the pigment.
scratching on the other parts of the body also needs to be controlled. loratidine will help with that.
but till the cause is found, appropriate treatment cannot be started. hence you can give me a few more details regarding that.
please let me know your queries too.