Solar Keratosis (Actinic keratosis)

Actinic keratosis (also called “solar keratosis” and “senile keratosis”) is a premalignant condition of thick, scaly, or crusty patches of skin. It is more common in fair-skinned people. It is associated with those who are frequently exposed to the sun, as it is usually accompanied by solar damage. Since some of these pre-cancers progress to squamous cell carcinoma, they should be treated. Untreated lesions have up to twenty percent risk of progression to squamous cell carcinoma.

Skin Care

The skin supports its own ecosystems of microorganisms, including yeasts and bacteria, which cannot be removed by any amount of cleaning. Estimates place the number of individual bacteria on the surface of one square inch (6.5 square cm) of human skin at 50 million, though this figure varies greatly over the average 20 square feet (1.9 m2) of human skin. Oily surfaces, such as the face, may contain over 500 million bacteria per square inch (6.5 cm²). Despite these vast quantities, all of the bacteria found on the skin’s surface would fit into a volume the size of a pea. In general, the microorganisms keep one another in check and are part of a healthy skin. When the balance is disturbed, there may be an overgrowth and infection, such as when antibiotics kill microbes, resulting in an overgrowth of yeast. The skin is continuous with the inner epithelial lining of the body at the orifices, each of which supports its own complement of microbes.

Light Sensitivity

Apart from vision, human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury. Some drugs have a photosensitizing effect. Properties of natural or artificial light that may abnormally affect people include:

Timing of light (upset of normal circadian rhythms, seasonal affective disorder, sleep disorders)
Intensity of light (photophobia, sunburn, skin cancer)
Wavelength of light ( in lupus, urticaria )
Rapid flickers in intensity of light may trigger or aggravate epilepsy or migraine headaches.
Other effects may include vertigo, or chronic fatigue syndrome.