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 symptoms and signs of rosacea tend to come and go. The skin may be clear for weeks, months, or years and then erupt again. Rosacea tends to evolve in stages and typically causes inflammation of the skin of the face, particularly the forehead, cheeks, nose, and chin. When rosacea first develops, it may appear, then disappear, and then reappear.