A reaction that your skin produces due to bacterial, fungal, viral, or parasitic contact is a skin infection. Skin infections can affect your body in several different ways, and some are more serious than others.
Actinic keratosis usually presents as a small, possible rough spot on the skin. These spots occur due to excess sun exposure. Actinic keratosis is often found on the face, scalp, ears, and back of the neck. These superficial lesions have not yet penetrated deeper into the skin.