Stasis dermatitis is a common chronic dermatosis that is seen almost exclusively on the lower extremities. The inflammation can lead to chronic discoloration, ulceration, and infection. Underlying systemic disease such as congestive heart failure and renal failure can predispose to stasis dermatitis. Any condition that can cause edema of the lower extremities has the potential to cause stasis dermatitis.
Clinical Findings: Stasis dermatitis is a chronic inflammatory skin disease that indicates underlying insufficiency of the venous return system. It is most commonly seen in the older population, and there is no gender or racial predilection. Most often, congestive heart failure is the associated disease causing the edema. Many other conditions of venous insufficiency can also be causative, including varicose veins and postsurgical complications, such as after a saphenous vein harvest for coronary artery bypass surgery or an inguinal lymph node dissection.
Stasis dermatitis is a skin manifestation of a wide range of underlying venous diseases. The lower extremities account for more than 99% of cases of stasis dermatitis, and the diagnosis in other areas of the body should be questioned. The legs tend to have a range of edema, from the very mild amount that accumulates at the end of a long day of standing to severe chronic edema that is always present. Red-brown patches, some with a light yellow discoloration, typically begin around the medial malleolus. As the condition progresses, the patches begin to spread and can encompass the entire lower extremity, although much more commonly they are found at knee level or just below knee level. There can be complete confluence of the dermatitis around the affected limb, or it can affect only part of the leg.
The rash is almost always symmetric, and it is not uncommonly misdiagnosed as bilateral lower extremity cellulitis. The rash is typically pruritic, and the itching can be so severe as to cause excoriations and small ulcerations. Depending on the severity, weeping vesicular patches and plaques can form. A rare bulla can also be seen in some cases, and one must consider bullous pemphigoid in the differential diagnosis. Varicose veins are often present on examination, or there may be a history of bypass surgery. If left untreated, venous stasis can lead to venous ulcerations, which have been described as slightly painful ulcerations on the lateral malleolus. The ulcerations can occur anywhere on the leg and in some cases are very tender. Peripheral pulses are intact, and this physical examination finding helps to rule out arterial insufficiency. If the ulcerations and edema are not controlled, the ulcerations will continue to expand and can become secondarily infected; if they become deep enough, they can lead to underlying osteomyelitis or cellulitis. These neglected cases can end in loss of the affected portion of the limb if medical therapies do not successfully clear the infection and ulcerations.
Pathogenesis: Increased pressure within the venous system of the lower extremity causes extravasation of serum and blood into the surrounding dermis and sub- cutaneous tissue. As the edema in the lower extremity worsens, the skin begins to develop signs of chronic inflammation mediated by the abnormal location of fluid.
Histology: Biopsies are not routinely performed in stasis dermatitis, and the diagnosis is almost always made clinically. Histological examination shows an increase in small vessels, extravasation of red blood cells, and hemosiderin deposition in the dermis. The epidermis shows varying amounts of spongiotic dermatitis.
Treatment: The rash can be treated symptomatically with topical corticosteroids and emollients. The main goal of therapy is to restore the proper venous flow.
Depending on the underlying reason for the stasis dermatitis, this may or may not be possible. If it is not possible, the mainstay of therapy is the use of compression stockings or wraps. However, the compliance rate is low because of difficulty putting them on and discomfort. Those patients who are able to use the compression gear and topical corticosteroids usually have a good prognosis.