Xerosis

Management Strategy

Initial evaluation should seek to distinguish simple xerosis from a genetic ichthyosis, although management is similar for both conditions. Family history, distribution, and morphology will help to differentiate the two. A history of weight loss, diarrhea, dietary history, and body mass index may give clues toward an underlying metabolic or malabsorptive disorder. Dry eyes and mouth may indicate underlying Sjögren syndrome. History and clinical examination should seek symptoms and signs of hypothyroidism, diabetes mellitus, and chronic renal disease. Drug use and sexual contact history may reveal HIV infection. Xerosis is an almost universal accompaniment of atopic eczema.

The mainstay of therapy for xerosis after any underlying disorders (if possible) are corrected is improvement of the humidity in the patient’s environment, avoidance of exacerbating factors such as soap and detergents, and the use of emollients or humectants .

Low environmental humidity both at home and work will exacerbate xerosis of any cause. Arid air is a problem in air-conditioned homes, offices, and vehicles. Hot, dry air directed to the lower legs during the winter in the front of automobiles is a common cause of lower leg xerosis. In the home or workplace, humidifiers can be fitted over radiators; alternatively, placing wet towels or containers of water over them will increase air humidity.

Soaps and detergents degrease the skin, reduce epidermal thickness, and increase scale and itch, and so are best avoided, and light emollient cleansers (soap substitutes) are suggested in their place. Bathing in tepid water is often preferred by patients, and patting the skin dry will produce less scale and dryness than vigorous toweling.

Emollients (which simply produce an impervious film over the epidermis and prevent ‘transpiration’) and humectants (such as lactic acid, urea, or glycerin that hold water in the epidermis osmotically) are the mainstays of therapy. Few good comparative studies exist for the most common type of xerosis, which is surprising because they are the most frequently used dermatologic products; indeed, a large review failed to justify recommendation of one constituent over another for foot xerosis. They should be used liberally and as frequently as possible and applied in the direction of hair growth; emollients are particularly valuable after bathing or showering to hold water in the epidermis. Light emollients for use in the shower or bath may be preferred to bath oils by some. Choice of emollient is entirely personal to the patient. A pack with small amounts of a variety of products for home trial or a self-selection ‘tub tray’ for the clinic is likely to enhance compliance. The best emollient is the one the patient likes; the most expensive is the one where 99% remains in the tub!

Agents containing α-hydroxy acids (AHAs) and ceramides may offer some advantages over conventional paraffin-based emollients, but this may be at the expense of irritation in some people. Low-concentration salicylic acid may help reduce scale in more severe xerosis, but it is essential to remember that systemic absorption and salicylism can occur.

Topical retinoids have only been used in the more severe ichthyoses and are too irritating for use in xerosis. Systemic therapies have little part to play in most patients.