Page 160 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 4-75 Integumentary System

STASIS DERMATITIS
Stasis dermatitis of the lower extremity appearing
as a hyperpigmented brown-red patch
Stasis dermatitis is a common chronic dermatosis that
is seen almost exclusively on the lower extremities. The
inflammation can lead to chronic discoloration, ulcer-
ation, and infection. Underlying systemic disease such
as congestive heart failure and renal failure can predis-
pose 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 accu-
mulates 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, typi-
cally begin around the medial malleolus. As the condi-
tion 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 Compression dressings or stockings are one of the best
below knee level. There can be complete confluence of ways to keep fluid from accumulating in the lower
the dermatitis around the affected limb, or it can affect extremities. Leg elevation is a mainstay of therapy.
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. Vari- Venous stasis ulcerations are one complication
cose veins are often present on examination, or there from long-standing or severe stasis dermatitis.
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 Ulcer
and edema are not controlled, the ulcerations will con-
tinue to expand and can become secondarily infected;
if they become deep enough, they can lead to underly-
ing 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 made clinically. Histological examination shows an Depending on the underlying reason for the stasis der-
serum and blood into the surrounding dermis and sub- increase in small vessels, extravasation of red blood matitis, this may or may not be possible. If it is not
cutaneous tissue. As the edema in the lower extremity cells, and hemosiderin deposition in the dermis. The possible, the mainstay of therapy is the use of compres-
worsens, the skin begins to develop signs of chronic epidermis shows varying amounts of spongiotic sion stockings or wraps. However, the compliance rate
inflammation mediated by the abnormal location dermatitis. is low because of difficulty putting them on and discom-
of fluid. Treatment: The rash can be treated symptomatically fort. Those patients who are able to use the compres-
Histology: Biopsies are not routinely performed in with topical corticosteroids and emollients. The main sion gear and topical corticosteroids usually have a good
stasis dermatitis, and the diagnosis is almost always goal of therapy is to restore the proper venous flow. prognosis.

146 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS