Abstract：
Disorders of hyperpigmentation are common and, depending on the extent and location of involvement, can affect the quality of life and pose a significant psychologic burden for patients. Given the similarities in presentation of the various causes of hyperpigmentation, it is often difficult to elucidate the etiology of these conditions, which is important to guide management. Furthermore, certain disorders, such as lichen planus pigmentosus and ashy dermatosis, have similar clinical and/or histologic presentations, and their classification as distinct entities has been debated upon, leading to additional confusion. In this review, the authors selected commonly encountered disorders of hyperpigmentation of the skin, subdivided into epidermal, dermal, or mixed epidermal-dermal disorders based on the location of pigment deposition, along with disorders of hyperpigmentation of the mucosa and nails. Melanocytic nevi, genetic disorders, and systemic causes of hyperpigmentation were largely excluded and considered to be outside the scope of this review. We discussed the pathogenesis of hyperpigmentation as well as the clinical and histologic features of these conditions, along with challenges encountered in their diagnosis and classification. The second article in this 2-part continuing medical education series focuses on the medical and procedural treatments of hyperpigmentation.
摘要：
色素沉着过度的疾病很常见，根据参与的程度和地点，会影响患者的生活质量，并给患者带来巨大的心理负担。鉴于色素沉着的各种原因的相似性，通常很难阐明这些疾病的病因，这对指导管理很重要。此外，某些疾病,如色素性扁平苔藓和灰白色皮肤病，有相似的临床和/或组织学表现，它们作为不同实体的分类一直存在争议，导致额外的混乱。在这次审查中,作者选择了常见的皮肤色素沉着过度疾病，细分为表皮，真皮,或基于色素沉积位置的混合表皮-真皮疾病，伴随着粘膜和指甲色素沉着过度的疾病。黑素细胞痣,遗传性疾病,色素沉着过度的全身性原因在很大程度上被排除,被认为不在本综述的范围之内.我们讨论了色素沉着过度的发病机理以及这些疾病的临床和组织学特征，以及在他们的诊断和分类中遇到的挑战。这个由两部分组成的继续医学教育系列的第二篇文章着重于色素沉着过度的医学和程序治疗。
