Topic Overview

Skin cancer is often or usually caused by years of too much
sun exposure. More than 90% of all skin cancers are found on body parts that
get the most sun most of the time. The face, neck, ears, hands, and arms are
common body parts that get skin cancer.

Skin cancer can often be
prevented by avoiding overexposure to the sun’s ultraviolet rays (UV rays). UV
rays from artificial sources, such as tanning beds or sunlamps, are just as
dangerous as those from the sun.

The three main types of skin
cancer are
basal cell cancer,
squamous cell cancer, and

ABCDE system is a guide to detect signs of skin cancer in moles or growths on
the skin.

  • Asymmetry. One half
    doesn’t match the other half.
  • Border irregularity. The edges are ragged, notched, or
  • Color. The pigmentation is not
    uniform. Shades of tan, brown, and black are present. Dashes of red, white, and
    blue add to the mottled appearance. Changes in color distribution, especially
    the spread of color from the edge of a mole into the surrounding skin, also are
    an early sign of melanoma.
  • Diameter. The
    mole or skin growth is larger than 6 mm (0.2 in.), or about the size of a
    pencil eraser. Any growth of a mole should be of concern.
  • Evolution. There is a change in the size, shape, symptoms
    (such as itching or tenderness), surface (especially bleeding), or color of a

People with
skin types that burn easily and do not tan are at
highest risk for skin cancers. Anyone who has had severe sunburns or many
sunburns is at high risk for skin cancers.

A person in the
southern United States has a 50% greater risk for getting basal cell cancer
than a person in the northern United States. The risk for squamous cell cancer
is four times greater in the southern U.S. The closer a person lives to the
equator, the greater the cancer risk from sun exposure. The risk for skin
cancer also increases if you are exposed to intense sun year after year over
your lifetime.


ByHealthwise Staff
Primary Medical Reviewer William H. Blahd, Jr., MD, FACEP – Emergency Medicine
Kathleen Romito, MD – Family Medicine
Specialist Medical Reviewer H. Michael O’Connor, MD – Emergency Medicine

Current as ofMay 3, 2017