Press "Enter" to skip to content

Post-Inflammatory Hyperpigmentation

  • Also known as post-inflammatory melanosis
  • Due to increased deposition or distribution of melanin following cutaneous trauma or inflammation

Etiology & Pathogenesis

  • Excess melanin deposition in the epidermis (epidermal melanosis) or dermis (dermal melanosis)
  • Coloration of the pigment depends on the depth of deposition
    • Epidermal melanosis appears tan, brown or dark brown
    • Dermal melanosis appears blue-gray

Epidermal Melanosis

  • Due to increased production and transfer of melanin from melanocytes to surrounding keratinocytes
  • Thought to be caused by melanocyte stimulation by inflammatory mediators
    • Arachadonic Acid Pathway
      • Leukotrienes
      • Prostaglandins
      • Thromboxane

Dermal Melanosis

  • Due to injury to basal keratinocytes
    • Causes release of excess melanin
    • Phagocytosed by macrophages
      • Become known as melanophages