Thanks for the query,
You might have developed an eczema.
It is an allergic reaction
to any antigen,
You have to try and notice whether you came in contact with a particular thing,
Or you have applied any new thing on scalp.
Apply a mild steroid
lotion like desonide
Also take an antihistamine tablet.
This will give you some relief.
Please meet a dermatologist
for exact diagnosis.
Let me know if you have any other doubt.
you can ask a direct question to me on this forum, following the below link.
Wishing you a good health.