Keratosis is sometimes misspelled as keritosis. This skin condition is basically an overgrowth of keratin on the skin.
What is keratin? Keratin is a tough and fibrous insoluble protein that is the main structural component of the epidermis (the outer layer of skin), nails, and hair.
When the keratin component of the skin grows faster than it should then this skin condition develops. There are several different forms of this skin problem.
Actinic or solar version of this skin problem is a pre-cancerous growth of thick patchy skin caused by overexposure to the sun. It is usually found on the face and hands and other areas that receive a lot of sun exposure. It commonly occurs in fair skinned individuals.
Pilaris or polaris type, as it is sometimes called, is characterized by the appearance of small bumps that are usually white in color. The bumps look like goose bumps or chicken skin. Usually these bumps are found on the backs of the upper arms, thighs, or buttocks areas.
The seborrheic version of this skin problem results in wart-like skin growths. Many can be present on the surface of the skin. They can be in a variety of different colors, but are generally benign and are not painful. However, the skin growths may be itchy and can be quite disfiguring.
This version of the skin disease is hereditary and originates in a hair follicle and often appears as dark crusty skin patches.
Senile type is related to the actinic or solar type. It is a term given to skin lesions appearing on the face and back of the hands of elderly individuals. It is brought on by prolonged sun exposure over the years. It is a pre-malignant or pre-cancerous skin condition.
Actinic cheilitis is essentially the same as actinic keratosis. The main distinction is that actinic or solar cheilitis targets the skin on the lips.