Extrinsic refers to external factors that impact skin health, such as our environment and lifestyle. Below are some of the major extrinsic causes of dry skin.
Weather / Environmental elements
Cold winds and low temperatures can dry out skin, depriving it of balanced levels of oils, and contributing to premature ageing.
Prolonged exposure to the sun causes water to evaporate from skin. Forced air heating also dries out skin: warm, dry air acts like a sponge, soaking up moisture from everything it touches.
The trend of low-fat or fat-free diets can deprive our bodies of skin-friendly Essential Fatty Acids (EFAs) critical to all parts of a healthy functioning body. They help protect against water loss within cells and throughout skin, helping to prevent dryness, keeping skin supple and hydrated. An EFA deficiency can result in chronic itching, dryness, scaling, and thinning.
Smoking can have a drying effect on skin: it drains skin and body of vitamins A and C and constricts blood vessels (which equates to less blood flow) – meaning smoking is somewhat like suffocating skin from the inside.
Excess intake of alcoholic beverages and certain medications (such as nasal decongestants) can also contribute to dry skin.