L3.5: Skin Color

• 3 pigments contribute to skin color

  • melanin
  • carotene
  • hemoglobin
• • Yellow, reddish brown, or black
  • People who produce a lot of melanin have brown skin
  • People with less melanin are light-skinned


  Melanin
• • Orange-yellow pigment from some vegetables
  • People who eat large amounts of carotene-rich foods tend to have a yellow-orange cast


  Carotene
• • Red coloring from blood cells in dermal capillaries
  • Oxygen content determines the extent of red coloring
  • In light-skinned people, it gives the skin a rosy glow

  Hemoglobin
• Skin color that signals certain disease

  • redness (Erythema)
  • Pallor (Blanching)
  • Jaundice (Yellow Cast)
  • bruises (black and blue marks)
• • Embarrassment (blushing)
  • Fever
  • Hypertension
  • Inflammation
  • Allergy


  redness (Erythema)
• • Emotional stress (fear, anger)
  • Anemia
  • Low blood pressure
  • Impaired blood flow into the area


  Pallor (Blanching)
• • Liver disorder
  • Excess bile pigments accumulate in the blood, circulate throughout the body, become deposited in body tissues


  Jaundice (Yellow Cast)
• • Hematomas
  • Deficiency of vitamin C
  • Hemophilia (Bleeder’s disease)


  Bruises (black and blue marks)