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.
The spots usually remain in the lower legs below the knees, but in more severe cases they can extend up the legs and onto the lower torso. The fading of the spots is a result of the absorption of the blood cells by the tissues over time. Unfortunately, as the spots fade, they may leave a brown pigmentation in the skin.