Hi.. It you are getting itching on hand & forehead due sunrays than there must problem in your body. you pitta dosha must be disturbed & due to this your blood may be impure according to ayurveda.
And you can't hide from Sunrays, you have take Ayurved treatment properly, do panch Karma also if needed.
Please consult Ayurvedic physician because he can treat root cause.
Next Steps
Ayurvedic physician is good choice.