Light Exposure

The sensitivity of humans to exposure to sunlight depends on the type of skin they are born with. Dermatologists divide people into 6 different photobiological skin types:

  • Type I: “Celtic”
    Very pale, extremely sensitive skin, freckles, blue or green eyes, blond to reddish-fair hair.
    Always sunburns, never tans. Has an auto-protection time (i.e. before the skin starts to go pink) of 5 to 10 minutes.
  • Type II: “Nordic”
    Pale, sensitive skin, sometimes freckles, fair or light brown hair, blue, grey or green eyes. Sunburns easily. Has an own auto-protection time of 10 to 20 minutes.
  • Type III: “Dark European”
    Pale to light brown, moderately sensitive skin, no freckles, fair to brown hair, grey or brown eyes. Sometimes sunburns. Has an auto-protection time of 20 to 30 minutes.
  • Type IV: “Light Mediterranean”
    Light to olive-brown, insensitive skin. Dark brown or black hair, usually dark brown eyes.
    Almost never sunburns. Has an auto-protection time of 30 to 40 minutes.
  • Type V: “Dark Mediterranean, Indian”
    Brown skin- irrespective of exposure to sunlight. Dark brown to black hair and dark brown eyes. Has an auto-protection time of over 40 minutes.
  • Type VI: “Negroid”
    Almost black, insensitive skin, black curly hair, dark brown to black eyes. Has an almost unlimited auto-protection time.

Central Europeans mostly fall within photobiological skin types I, II and, above all, III. Type IV pigmentation is found among southern Europeans, pigmentation type V among strongly pigmented southern Europeans, North Africans, South Americans and Asians, and pigmentation type VI among black Africans and Afro-Americans.

Photodermatosis (sun allergy) is mostly caused by UVA radiation (60 %), partly by UVB radiation (20 %), and partly by UVA and UVB radiation together (20 %). Sun allergies begin with strong itching, followed by a rash of small and then bigger blisters. Sun allergies produce similar symptoms, but may have different causes. Polymorphic light eruption is caused by the sun, “Mallorca acne” by the sun in combination with skin care agents, and photoallergic and phototoxic reactions by the sun in combination with medication, food additives, plants and plant products, etc.