22 Asteatotic Eczema (Xerosis, Xerotic Eczema, Eczema Craquelé, Eczema Cannalé, Eczema Hiemalis, Winter Itch) INTRODUCTION This common dermatitis is often misdiagnosed and usually overtreated. Familiarity with the physical findings will allow an accurate assessment of the underlying cause, and symptoms can usually be corrected with simple measures. The condition occurs for a number of reasons, especially the following: 1. With age, skin sebum secretion diminishes, as does the water-holding capacity of the epidermis. These changes are particularly marked on the lower extremities. 2. Bathing further depletes the epidermis of its water-retaining constituents. 3. Climate has a major effect, and most patients experience symptoms for the first time during a winter season as their skin dries from exposure to the low indoor humidity produced as buildings are heated against inclement weather. Incidence will vary from place to place, depending on the severity of the season and the overall regional weather. CLINICAL APPLICATION QUESTIONS In the early spring, a 75-five-year-old woman visits your office with a complaint of generalized itching. The symptoms began in late December on local skin areas, and have progressed throughout the winter. You suspect an asteatotic eczema. 1. What information from her history may help support your suspicions? 2. What are the primary lesions in areas of asteatotic eczema? 3. What are the secondary lesions seen in asteatotic eczema? 4. What typical configurations strongly support your suspicions? 5. This woman has minimal physical findings, and some provoking factors are evi- dent in her history, but she fails to improve with treatment. What should be done next? APPLICATION GUIDELINES Specific History Onset Symptoms usually are noted in the fifth and sixth decades of life for the first time. The incidence and severity of symptoms gradually increase with advancing age. Persons with From: Current Clinical Practice: Dermatology Skills for Primary Care: An Illustrated Guide D.J. Trozak, D.J. Tennenhouse, and J.J. Russell © Humana Press, Totowa, NJ 213 214 Part IV / Epidermal, Dermal, Eczematous Lesions, Atrophies inherently dry skin will experience problems at a younger age and earlier in a given sea- son than those without this constitutional predisposition. The first victims usually present about midwinter, and new cases will continue to present until the spring weather pattern is established and indoor heating is curtailed. Onset can be quite abrupt in elderly patients during hospital stays. Hospitals are often kept uncomfortably warm, and because of the large central heating plant, have a low ambient humidity. Early symptoms consist of intense itching of the extremities and axillary folds, and patients will often remark that their skin feels dry. A generalized gray or white powdery sheen is evident, and the skin surface has a dull, lifeless appearance. The itching from dry skin can be as severe as that from the worst drug reaction. Evolution of Disease Process If the early signs and symptoms of asteatosis are not recognized, the symptoms will generalize and the patient will complain of discomfort that may seem to exceed the phys- ical findings. These symptoms are often mistaken for hypersensitivity reactions leading to the discontinuation of important medications. Evolution of Skin Lesions Without treatment, the condition of the epidermis will deteriorate from a dry sheen to a stage where it can no longer maintain its surface integrity. At this point, plates of epi- dermal cells lift up, producing a coarse white scale. Later fissures develop into a canal- like (cannalé) or crazy-paving (craquelé) pattern. These changes most often start as discrete patches on the lower extremities, but with time or in severe cases, may be gener- alized. Persistent fissures will become inflamed and erythematous, or even frankly eczematous, with changes of edema and serous exudate. Scratching may introduce an ele- ment of superficial secondary infection (impetiginization), which further excites the inflammatory reaction and promotes spread of the lesions. Provoking Factors 1. Constitutionally dry skin. 2. Arid climate conditions. 3. Long inclement spells of wet or cold weather, which increase indoor heating demands. 4. Heating systems that deplete indoor humidity (fireplaces, wood stoves, and gas logs). 5. Excessive bathing. 6. Malnutrition (rare). 7. Medications including allopurinol, cimetidine, dixyrazine, lithium, nicotinic acid, clofibrate, and other cholesterol-lowering agents. Self-Medication Self-treatment can be a significant problem. Many patients will use OTC itch creams that contain highly sensitizing substances such as benzocaine or diphenhydramine. This can lead to a superimposed allergic contact dermatitis. It is sometimes difficult to convince patients that their severe pruritus is due simply to dry skin. Find out what they are using and take control of the situation. Some OTC hydrocortisone creams, for instance, have Chapter 22 / Asteatotic Eczema 215 cream bases that are more irritating than the anti-inflammatory effect of the active ingre- dient, and would contribute to rather than resolve this problem. Supplemental Review From General History If changes and symptoms of asteatosis respond promptly to treatment, no additional investigation is indicated. Generalized pruritus without changes of asteatosis, and acquired ichthyosis can be signs of underlying systemic disease. If either are present with- out signs of asteatosis, or if an asteatotic patient continues to have severe pruritus once the dryness is corrected, then a complete history and general physical examination should be done along with a basic CBC, chemistry panel, and a thyroid function panel. Further investigation should be based on findings from that examination. Dermatologic Physical Exam Primary Lesions 1. Patches of skin that appear dull, fissured, scaly, erythematous, or impetiginized (see Photos 44,45). 2. Intervening skin that shows an accentuated dull crisscross pattern of skin mark- ings (see Photo 44). Secondary Lesions 1. Fine white scale (early). 2. Coarse white scale (later). 3. Fissures may be dry or exudative and eczematous. Color of the fissures varies from pink to a deep dusky red. They may contain small amounts of hemorrhage or exudate. The fissures often produce a canal-like (see Photo 46) or crazy- pavement (see Photo 47) pattern. This craquelé pattern has also been described as resembling the surface fractures on an old piece of Chinese pottery. 4. Impetiginization. Distribution Microdistribution: None. Macrodistribution: The lower extremities, thighs, and hips are the most common sites. Axillary folds and proximal arms are next. Distribution may be generalized in severe cases (see Fig. 7). Configuration The canal-like and crazy-paving patterns are virtually diagnostic (see Photos 46,47). Indicated Supporting Diagnostic Data None. Therapy Prevention Unless you explain to the patient and relatives the underlying etiology of the disorder, the problem will recur. Bathing habits should be reviewed; the patient should be using a 216 Part IV / Epidermal, Dermal, Eczematous Lesions, Atrophies Figure 7: Macrodistribution of asteatosis. mild bath bar with moisturizing ingredients. Showers are less drying than tub bathing. Spas and hot tubs should be discouraged. Emollients and medications must be applied immedi- ately after toweling before the skin really dries if they are to be maximally effective. Explain the effect of dry heating sources, and encourage the use of a humidifier. Cold-water vaporizers are an inexpensive means of raising humidity, and they are portable and safe. A central humidifier attached to the furnace is ideal, but is a substantial expense. Small room humidifiers work well, but again they are expensive and have ongoing upkeep costs. Topical Steroids Corticoids will suppress inflammation but will not correct the underlying dryness. They should be reserved strictly for the inflamed or frankly eczematous lesions. You may use group VI or VII steroid creams for this purpose, and try to choose those with an emol- lient base. These products have enough potency to correct the inflammatory changes, and Chapter 22 / Asteatotic Eczema 217 virtually no risk of secondary atrophy. They should be applied to the inflammatory lesions only, and should be followed immediately with a general application of moisturizer. Moisturizers Lubricants are the real therapeutic mainstay for correcting dry skin. Two factors must be considered when recommending a lubricant: (1) it must correct the dryness, and (2) it must have enough patient acceptance that it will be used regularly. Two effective emol- lients are Original Formula Eucerin® cream and Cetaphil Moisturizing Cream®. These should be applied initially TID over any dermatitic sites that have just been treated with the topical corticoid. As areas of asteatosis improve, the topical steroid is gradually dis- continued. Moisturizers must initially be applied in a general fashion two or three times daily and immediately after toweling. Once asteatosis is corrected, nightly application may be sufficient. Several products are available OTC that contain either an α-hydroxy acid or urea as active ingredients. Both ingredients improve the water-holding capacity of the epidermis. These active agents have a definite long-term beneficial effect on the appearance and func- tion of the epidermal surface. Products are available OTC containing 5 to 10% lactic acid, and there is a cream preparation