Cutaneous Amyloidosis
摘要
Amyloidosis comprises a group of disorders characterized by aberrant extracellular deposition of amyloid. Skin lesions may be classified into primary localized cutaneous amyloidosis (PLCA) or, less commonly, systemic amyloidosis. Cutaneous findings in primary systemic amyloidosis include periorbital purpura and waxy, translucent, flesh-colored to yellowish papules or plaques. Secondary systemic amyloidosis rarely presents with cutaneous findings but may demonstrate nonspecific petechiae or purpura. Discussion includes the three variants of PLCA: lichen, macular, and nodular. For each subtype, we review their etiology and pathogenesis, morphology, associated conditions, histopathology, evaluation, and management, with special emphasis regarding older patients. While the clinical manifestations remain the same, the cutaneous lesions of amyloidosis can be mistaken for benign age-related changes in older patients. In this population, management should consider factors such as increased skin fragility and sensitivity to adverse effects of systemic agents including anticholinergics.