causes of spots on the
Skin Diseases That Cause Dark Spots. 1  Melasma: Itâs one of the commonest causes of grayish patches on the face. 2  Riehlâs Melanosis: It causes grayish or brownish patches on your face resulting from hyper-pigmentation. 3  Poikiloderma of Civatte: This mostly affects the neck area that has been exposed to sunâs rays.