Factors Contributing to Skin Color

Major Pigments

1. Melanin

   • Produced by melanocytes in the epidermis.
   • Packaged into melanosomes, incorporated into keratinocytes to shield DNA.
   • Sun exposure increases melanin production.
   • Two forms: reddish-yellow and brownish-black.
   • Skin color differences due to amount and form of melanin.
   • Freckles and moles are local melanin accumulations.

2. Carotene

   • Yellow to orange pigment, visible in palms and soles.
   • Accumulates in the stratum corneum and hypodermis.
   • Can be converted to Vitamin A for vision and skin health.
   • High beta-carotene intake can make skin yellow to orange.

3. Hemoglobin

   • Provides a pinkish hue, especially noticeable in lower melanin levels.
   • Caucasian skin is more transparent, showing hemoglobin color more.

Alterations in Skin Color

• Cyanosis

  • Bluish skin due to low oxygenation of hemoglobin.

• Erythema

  • Redness due to increased blood flow (causes: fever, hypertension, inflammation, allergy).

• Pallor

  • Pale skin due to blood flow diversion (causes: anemia, low blood pressure, fear, anger).

• Jaundice

  • Yellowing due to bilirubin accumulation (associated with liver disorders).

• Bronzing

  • Due to inadequate steroid hormones (example: Addison's disease).

• Bruises

  • Black and blue marks from blood clots beneath the skin surface (hematomas).