Part I. Changes in Nail Color and Vasculature as Signs of Systemic Disease.

Nail changes are often associated with systemic disease, and are sometimes one of the earliest clues. Nail examination is often overlooked in clinical practice, and there remains a significant gap in dermatology educational curricula on diagnosis and management of nail disorders. The purpose of this review is to describe salient nail signs which can provide clues to the physician for the diagnosis of a systemic disorder. In Part I of this two part continuing medical education series, we review changes in nail color and vasculature known to be associated with systemic disease. Prompt recognition of these signs on routine physical examination is important for suspecting underlying diseases and improving patient outcomes. We also describe clinical algorithms to approach these salient nail findings to help physicians perform appropriate workup or referral to physician specialists.