The skin frequently serves as a marker for underlying internal disease. The type of lesion typically relates to a specific disease or type of disease.
(See also Evaluation of the Dermatologic Patient.)
Patients with dermatomyositis who are over age 40 have an increased risk of breast, lung, ovarian, and gastrointestinal cancers.
Acute onset of multiple seborrheic keratoses (Leser-Trélat sign) may indicate underlying internal cancer, particularly adenocarcinoma. However, because of the high prevalence of seborrheic keratoses in healthy adults, this sign may be overdiagnosed.
Acute febrile neutrophilic dermatosis (Sweet syndrome) is sometimes associated with hematologic cancer.
Acanthosis nigricans that is associated with cancer can be of rapid onset and particularly widespread. Acquired ichthyosis or pruritus without a clearly associated dermatitis may indicate occult cancer, often lymphoma.
Paraneoplastic pemphigus is a relatively rare autoimmune blistering disease that has been associated with various cancers, including leukemias.
Carcinoid syndrome (flushing and erythema of the neck) is associated with carcinoid tumor.
Erythema gyratum repens is a rare eruption consisting of concentric erythematous lesions, resembling wood grain, which has been associated with various cancers.
Many skin findings are associated with endocrinopathies but are not specific.
Patients with diabetes mellitus may have acanthosis nigricans, necrobiosis lipoidica, perforating disorders, and scleredema.
Cushing syndrome causes striae distensae, moon facies, and skin fragility.
Addison disease is characterized by hyperpigmentation that is accentuated in skin creases and areas of trauma.
Skin conditions commonly associated with GI disorders include