Dermatologic Manifestations in Patients with Systemic Disease

Because of the frequency of skin involvement in systemic diseases, cutaneous manifestations often prove very helpful in establishing the correct diagnosis. The skin signs of systemic disease can be specific, e.g. cutaneous lupus erythematosus, cutaneous sarcoidosis, in part because of associated histologic features, while others are best described as suggestive, e.g. pyoderma gangrenosum, acquired ichthyosis. Cutaneous findings that raise the possibility of an underlying malignancy, referred to as paraneoplastic, can serve as an early warning sign, appearing prior to the diagnosis of the associated malignancy. In general, paraneoplastic skin diseases improve if the associated malignancy responds to appropriate therapy and their recurrence should prompt a thorough search for recurrence of the cancer. In this chapter, the characteristic dermatologic manifestations of rheumatologic, hematologic/oncologic, gastrointestinal, and cardiopulmonary disorders are reviewed, with cross references to more detailed descriptions in chapters throughout the book.