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.
A Dr. Mehmet Oz, MD , Cardiology (Cardiovascular Disease), answered. The white patches caused by the skin condition vitiligo can spread to other locations or can stay in one area. The course is unpredictable and varies from person to person. Some people with vitiligo say that new patches form on skin that is under pressure or exposed to friction. This can happen from shaving or rubbing from jewelry or clothing.