Heterogeneous Pathology of Melasma and Its Clinical Implications

Int J Mol Sci. 2016 May 26;17(6):824. doi: 10.3390/ijms17060824.


Melasma is a commonly acquired hypermelanosis that affects sun-exposed areas of the skin, with frequent facial involvement. Its histologic manifestations are evident in the epidermis, extracellular matrix, and dermis. In addition to epidermal pigmentation, pathologic findings of melasma include extracellular matrix abnormality, especially solar elastosis. The disrupted basement membrane has been described in melasma with variable incidences. In the dermis, an increase in vascularity and an increase in the number of mast cells were observed, indicating that dermal factors have critical roles in the pathogenesis of melasma, despite the fact that melasma is characterized by epidermal hyperpigmentation. This review discusses such histologic characteristics of melasma, with consideration to their implications for melasma treatment.

Keywords: basement membrane; histopathology; mast cells; melasma; photoaging; vascularization.

Publication types

  • Review

MeSH terms

  • Administration, Topical
  • Antioxidants / administration & dosage
  • Antioxidants / therapeutic use
  • Basement Membrane / metabolism
  • Basement Membrane / pathology
  • Chloroquine / administration & dosage
  • Chloroquine / therapeutic use
  • Dermis / metabolism
  • Dermis / pathology
  • Disease Management
  • Gene Expression Regulation
  • Humans
  • Hydroquinones / administration & dosage
  • Laser Therapy
  • Mast Cells / metabolism
  • Mast Cells / pathology
  • Melanosis / metabolism
  • Melanosis / pathology*
  • Melanosis / therapy*
  • Phototherapy


  • Antioxidants
  • Hydroquinones
  • Chloroquine
  • hydroquinone