Skin manifestations of internal disease.

Internal diseases can manifest in a myriad of skin dermatoses ranging from single disorders such as calciphylaxis, cryoglobulinemia, amyopathic dermatomyositis, and Raynaud phenomenon, to spectrum disorders such as the neutrophilic dermatoses and morphea. In this article the underlying causes, triggering events, constitutional symptoms, clinical features and presentations, appearance at various stages, and pathogenesis are described. The course of the diseases and probable healing outcomes are outlined. Finally, examination and diagnostic methods, and therapies and treatments are provided.