Hi, thanks for posting your query to us.
You seem to have increased sensitivity to sun light ( means you are allergic to sunlight). The changes that you have described when you go out in sun that is dryness , redness
, itching, are due to the effect of UVA and UVB rays on the exposed parts of the skin. This is called polymorphic light eruptions.
To treat the same:
First thing is to avoid sun exposure especially from 10 am to 3pm when sun rays are most harmful.
Apply a sunscreen lotion in the morning , repeat it every 3-4 hours during the day time. For a sunscreen to be effective it should be applied half an hour before you go out.
On the red and dry spots you may apply a steriod
cream by doctor's advice.
Don't scratch the itchy spots, as they may worsen the problem and leave brown spots which lighten very slowly even after treatment.
You may contact a dermatologist
for most suitable sunscreen according to your skin type and the steroid
I have tried to write in a very simple way for you, I hope you understood it but still if you have any doubt, please let me know.