Melanonychia is a black or brown pigmentation of the normal nail plate, and may be present as a normal finding on many digits in Afro-Caribbeans, as a result of trauma, systemic disease, or medications, or as a postinflammatory event from such localized events as lichen planus or fixed drug eruption.
许多患者对黑甲症感到担忧,因为它会使指甲板呈现棕黑色。黑甲症是导致指甲变色的常见原因,病因范围从良性到潜在的严重疾病,如黑色素瘤。纵向带状黑甲症可能由多种局部或全身因素引起。 Melanonychia is a very worrisome entity for most patients. It is characterized by brownish black discoloration of nail plate and is a common cause of nail plate pigmentation. The aetiology of melanonychia ranges from more common benign causes to less common invasive and in situ melanomas. Melanonychia especially in a longitudinal band form can be due to both local and systemic causes.
Melanonychia represents a brown to black discoloration of the nail plate that may be induced by benign or malignant causes. Two main mechanisms are involved in the appearance of melanonychias, i.e., melanocytic activation and melanocytic hyperplasia.
如果甲周组织出现宽而深的色素带,伴有不规则的线条和色素延伸,则可能提示黑色素瘤。