Nail Signs longitudinal melanonychia 纵向黑色素

Longitudinal melanonychia results from melanin production by nail matrix melanocytes and is most commonly due to simple activation of these melanocytes. It can also result from melanocyte hyperplasia as is found in a lentigo, nevus or melanoma. Clinically, melanonychia presents as one or more longitudinal pigmented bands extending from the proximal nail fold to the distal margin. The band of melanonychia can vary in color from light brown to black and the pigmentation may be homogeneous or variable. The width ranges from a few millimeters to the whole nail width. Single band may be a sign of melanocyte activation or proliferation (nevus, melanoma). Multiple bands point to physiologic, trauma/onychotillomania, drugs or systemic disease.

Common causes of Longitudinal melanonychia:

Trauma (manicure, nail biting/onychotillomania, friction, primarily in toenails) Drugs [cancer chemotherapeutic agents, zidovudine (AZT), psoralens] Radiation, Pregnancy, Laugier–Hunziker syndrome, Peutz–Jeghers syndrome, Addison disease, HIV infection, Postinflammatory [lichen planus, pustular psoriasis, onychomycosis (T. rubrum and Scytalidium spp.)], Bowen disease, Onychopapilloma, Onychomatricoma, Nail matrix lentigo, Nail matrix nevus, Nail matrix melanoma.

Longitudinal melanonychia

纵向黑色素(Longitudinal Melanonychia)最常见的原因是这些黑素细胞的活化。 它也可以由雀斑，痣或黑色素瘤中的黑素细胞增生引起。 临床上，黑色素呈现为从近端指甲褶皱延伸到远端边缘的一个或多个纵向色素带。 黑色素的颜色可以从浅棕色到黑色变化，并且色素沉着可以是均匀的或可变的。 宽度范围从几毫米到整个指甲宽度。单一条带可能是黑素细胞活化或增殖的标志（痣，黑素瘤）。 多个条带指向生理，创伤/甲状腺功能亢进，药物或全身性疾病。

病因：创伤（修指甲，咬指甲/甲状腺功能躁狂，脚趾甲摩擦），药物 （癌症化疗药物，齐多夫定，补骨脂素），放射，妊娠，Laugier-Hunziker综合征，Peutz-Jeghers综合征，艾迪生病，HIV感染，炎症后 （扁平苔藓，脓疱性牛皮癣，甲癣），Bowen病，Onychopapilloma，Onychomatricoma，指甲基质雀斑，指甲基质痣，指甲基质黑色素瘤。

Reference:

 

  1. Antonella Tosti, Bianca Maria Piraccini. In: Jean Bolognia Julie Schaffer Lorenzo Cerroni, editors. Dermatology: 2-Volume Set 4th Edition. Elsevier; 2017. p1204-1205.
  2. N Di Chiacchio, BS Ruben, WR Loureiro: Longitudinal melanonychias. Clin Dermatol. 31:594-601 2013