CASE # 2: Stasis dermatitis
A type of spongiotic dermatitis that almost always occurs on the leg, stasis dermatitis (SD) is thought to be related to chronic venous insufficiency with venous hypertension. An age-related decrease in valve competency is usually to blame.
SD plaques are often scaly, rough, dry, red, or pruritic; some are moist, oozing crusts and erosions. Usually an isolated condition, SD can be associated with lymphedema, cellulitis, venous leg ulceration, atrophie blanche, and lipodermatosclerosis. Besides venous insufficiency, underlying conditions include diabetes, hypertension, peripheral vascular disease, high lipid levels, morbid obesity, and cardiac failure.
In the United States, SD occurs in 6%-7% of persons aged 50 years and older. After age 70, the prevalence may be >20%. Women are slightly more likely to be affected, perhaps due to the effect of pregnancy on the venous system of the leg. Deep venous thrombosis (DVT), vein stripping, saphenous-vein harvesting, or traumatic injury can severely impair the function of the lower-extremity venous system, leading to SD. In persons younger than 50, SD is more often related to surgery, trauma, a history of DVT, or repeated cellulitis.
The first symptom is pruritus, followed by scaly pink, red, erythematous, and/or brown plaques, which can be associated with edema. Rarely, SD can manifest with red friable and purple nodules termed pseudo-Kaposi sarcoma or acroangiodermatitis. SD often manifests first on the medial ankle, the foot, or the calf and extends to the knee. The id reaction is a papular eruption distant from the SD itself.
Differential diagnoses include asteatotic eczema, cellulitis, allergic contact dermatitis, necrobiosis lipoidica, nummular dermatitis, benign pigmented purpura, and pretibial myxedema. Staphylococcal superinfected SD with its telltale yellow crusts must be distinguished from cellulitis. A classic inverted champagne-bottle appearance identifies lipodermatosclerosis, which, like cellulitis, involves the dermis and fat.
One proposed etiology of SD involves pericapillary fibrin cuffs, which may act as a barrier to the diffusion of oxygen and nutrients, resulting in tissue anoxia, intracellular spongiosis, cell death, and sometimes ulceration. Whether pericapillary fibrin cuffs are barriers or markers for endothelial cell damage or part of an overall mechanism of macromolecular leakage and trapping is uncertain. Leg ulcers resulting from causes other than venous hypertension do not possess fibrin cuffs. Other hypotheses include the trapping of growth factors by macromolecules that have leaked from the vasculature and damage to epithelial cells in the microcirculation due to adherence of WBCs. Secondary or acute-onset SD may result from impaired deep venous circulation, a hypercoagulable state, DVT, or severe valve damage due to past thrombosis.
Treatment of SD depends on its stage, duration, and underlying conditions. Elastic support hose worn to at least knee height at 30 mm of pressure can help reduce edema and improve venous return. Raising the lower extremities above the level of the heart when sitting and minimizing standing reduces fluid buildup. If erythema is a prominent manifestation, low- and medium-potency topical corticosteroids can help reduce inflammation. I often start the patient on triamcinolone 0.1% cream (Kenalog), then taper to hydrocortisone valerate cream 0.2%. Dry-skin care using only mild soaps or cleansers and bland emollients (such as petrolatum) after showering or bathing is sometimes helpful. Complex moisturizers and topical antibiotics can induce allergic contact dermatitis.
SD is usually a progressive and chronic condition that re-quires lifelong care. If superinfection and cellulitis are present, they must be treated to avoid exacerbation of the SD.
This patient's erythema abated with two weeks of triamcinolone 0.1% cream, but the underlying brawny dyspigmentation and lichenification remained.
Dr. Scheinfeld is assistant clinical professor of dermatology at Columbia University in New York City, where he has a private practice.