More specifically, there are a few conditions which can cause excessive oiliness which causes seborrheic melanosis of the face. This appears as overall skin dullness, with an increased pigmentation on the central forehead and the T zone of the face. Pigmentary demarcation lines occur as darker patches of skin over certain zones of the face. These appear typically in a spectacle pattern -around the eyes, and extending onto the temples on the sides. Conditions like diffuse and early melasma, may also cause patchiness of the skin. Some people experience a face-neck mismatch, most commonly arising from hormonal imbalances or improper use of bleaching creams and serums. Allergy to hair color may also cause uneven skin tone in the early stages, before pigmentation becomes more prominent.