Firstly it is important to know the indication for which you are using mometasone
cream....Mometasone cream is a topical steroid
which is usually prescribed over face in case of any eczemas....Now in your case, seems like you have some photodermatitis over your face because of which you develop redness
, itching and irritation over face on exposure to sunlight,,,I would advise you to use a sunscreen (SPF>26) regularly before going out in the skin ....It will help to reduce the photosensitivity
...and you may continue to use mometasone cream at night....
Hope it helps
Dr Geetika Paul