A value of NULL indicates that the value is unknown. A value of NULL is different from an empty or zero value. No two null values are equal. Comparisons between two null values, or between a NULL and any other value, return unknown because the value of each NULL is unknown.
Skin Spots on the Face. Most causes of spots on face are harmless. They can be a variety of colors including white, red, black or brown. Common causes include cumulative sun exposure, acne, and skin tags. Keratoacanthoma (hyperkeratosis) is a lesion that grows rapidly, usually on areas exposed to the sun.
Other Oily Face Conditions. In addition to pimples, increased oil can cause flat areas of inflammation on the skin. In the midline this is called seborrheic dermatitis; in the butterfly area of the nose and the skin next to it, the inflammation is called acne rosacea.