There is a tendency to trivialise the skin, says Peter Elias, a dermatologist at the University of California, San Francisco. And yet, this largest organ of the body is vital to health, keeping moisture in and germs out. There are many things that can interfere with these functions. Dry weather draws moisture from the skin. Bathing or showering too often—more than once per day—or using harsh cleansers that strip away naturally-occurring oils, can also cause problems. When the skin becomes too dry, it can become itchy and inflamed. Dryness can also cause cracks in the skin which can lead to infections.