Key Clinical Questions
What are the most common cutaneous manifestations of gastrointestinal, renal, rheumatologic, and endocrinologic disease? What are rare but important cutaneous findings which should not be missed?
How does systemic amyloidosis manifest in the skin?
What key features are necessary to recognize nutritional deficiencies?
What is the systemic approach to purpura?
When should an inpatient dermatology consultation be obtained?
This chapter will focus on the integument and its unique ability to exhibit disease that lies beneath. A lesion may represent skin involvement from an internal condition, such as amyloidosis or cutaneous metastases, or a reactive process to underlying disease, such as neutrophilic dermatoses related to inflammatory bowel disease, or cutaneous vasculitis due to drug hypersensitivity. Cutaneous lesions can also be characterized as specific to an underlying systemic process, or as nonspecific manifestations that may occur in many disorders. Skin findings may represent the sole clinical manifestation of a systemic disorder. A basic knowledge of these conditions is essential not only for recognizing an underlying association, and for determining when an inpatient dermatology consult may be useful in the diagnosis and management of an otherwise puzzling patient.
CUTANEOUS MANIFESTATIONS OF GASTROINTESTINAL DISEASE
Disorders in which vascular lesions are found in both skin and viscera may present with gastrointestinal (GI) hemorrhage. Though rare, these disorders should be considered in patients with gastrointestinal bleeds, particularly in the setting of recurrent bleeds, family history of hemorrhage, or multiple vascular lesions on the skin.
Telangiectasia in the setting of GI or pulmonary vascular lesions raises suspicion for hereditary hemorrhagic telangiectasia (HHT, also known as Osler-Weber-Rendu syndrome). This is a familial autosomal dominant or spontaneous disorder, characterized by cutaneous telangiectasias and visceral arteriovenous anomalies. Epistaxis in childhood is often the presenting sign, followed by the development of well-defined 2 to 3 mm macular or papular telangiectasias on the face, lips, tongue, ears, and chest during late childhood to young adulthood (Figure 149-1). Telangiectasias represent dilations of the superficial capillary network, which typically blanch upon pressure. Gastrointestinal bleeding from mucosal telangiectasias occurs in about 20% to 40% of cases, with onset typically after the fourth decade. The stomach and duodenum are often sources of this potentially life-threatening bleeding. Additional visceral manifestations of HHT include hepatic or pulmonary arteriovenous fistulae, which may lead to shunting, dyspnea, hemoptysis, or systemic embolism and infection, and cerebral arteriovenous malformations, which may lead to intracranial hemorrhage.
Telangiectasia on the ear of a patient with hereditary hemorrhagic telangiectasia.
Blue rubber bleb nevus syndrome (BRBNS) is a spontaneous or autosomal dominant inherited disorder characterized by venous malformations of the skin, GI tract, and other viscera. Cutaneous findings include multiple dark blue to violaceous compressible, rubbery skin lesions known as blebs, ...