++
Frequently, cutaneous findings are relevant to the overall health of a patient. Even though some findings on the skin are the result of multisystem disease processes that affect the whole organism, primary skin diseases may also impact other organs and overall health, particularly when severe or longstanding.
++
A comprehensive chapter on cutaneous manifestations of systemic disease could encompass much of dermatology. This chapter’s goal is to provide general information and principles, highlight key diseases that may not be discussed elsewhere, and group disorders into quick-reference charts organized by organ system. This chapter specifically focuses on cutaneous manifestations of cardiovascular, pulmonary, hepatic, GI, and renal disease.
+++
CARDIOVASCULAR SYSTEM
++
Disturbances in the cardiovascular system causing decreased cardiac output can produce marked skin changes. Cyanosis is a purple-blue discoloration of the skin caused by an increase in the absolute amount of desaturated hemoglobin. It can be classified as “central,” in which low arterial oxygen saturation is caused by lung disease or shunt physiology, or “peripheral,” in which arterial oxygen saturation is normal but flow is reduced because of low-output cardiac failure or vasoconstriction. Central cyanosis is usually visible in warm areas of the skin, like the tongue, oral mucosa, and conjunctivae. Peripheral cyanosis is seen in cooler areas such as the nose, lips, earlobes, and fingertips.
++
In the acute setting (shock), the extremities can become cool and clammy with associated peripheral cyanosis, livedo, and mottling. If severe, this can progress into gangrene of the digits. Vasopressor medications used to support the blood pressure can exacerbate this problem by causing peripheral vasoconstriction. Chronic poor peripheral blood flow from heart failure or peripheral vascular disease can produce chronic edema, venous stasis, decreased hair, and ulceration of the lower legs.
++
Nail changes associated with cardiovascular disease include clubbing and the Quincke pulsation, which is flushing of the nail beds synchronous with the heartbeat, indicative of aortic regurgitation.
++
Table 133-1 outlines select conditions with cardiovascular and cutaneous manifestations.
++