Aging & Health A to Z
Causes & Symptoms
Most skin cancers, particularly basal cell and squamous cell types, are caused by exposure to sunlight. The ultraviolet rays of the sun—particularly UVB and UVA wavelengths—cause DNA damage in the cells. The resulting lesions usually occur on areas of the skin that have received the most sun exposure. These are typically the face, the back of the hands, and the arms. Your chances of having a skin cancer increases with age and lifetime sun exposure.
Besides sunlight, being in contact with certain chemicals or taking medications that suppress your immune system can also increase your risk of getting skin cancer.
The following risk factors may increase your chance of developing skin cancer:
- Light skin color
- Red or blond hair
- Long-term sun exposure
- Having had severe, blistering sunburns in childhood
- Increasing age
- Certain genetic patterns that may run in families
- Exposure to specific chemicals (such as arsenic) or radiation
- Having a compromised immune system
- Presence of certain types of skin abnormalities such as actinic keratoses (rough, red scaly patches)
- Cigarette smoking
- Family history of skin cancer
- Tanning booths or use of tanning lamps
- Presence of wounds or scars that will not heal
Symptoms and Warning Signs
The following signs may be early indicators that you have skin cancer or that a skin cancer may develop in the future. (They are often painless, but sometimes may be tender to the touch):
- A waxy, pearly pimple on the skin covered with splotchy enlarged blood vessels and with a “rolled” border
- A scar-like abnormality
- Reddish patch (flat or slightly raised)
- Rough, scaly, or crusted areas
- Thick, horny growths
- Wounds that ooze and do not heal after a reasonable time
- Patch or mole that seems newly pigmented (darkened)
- Changes in color, size, surface, or borders of a mole
You can remember the warning signs for melanoma by recalling the letters “ABCD”. They stand for:
- Asymmetry (uneven or irregular shape)
- Borders (uneven)
- Color (tan, brown, gray, black or blue-black – may be quite varied)
- Diameter (more than about a quarter of an inch).
Older adults over 65 years of age should also check for dark brown or black patches on the palms of the hands, soles of the feet, or on the nail beds of the fingers or toes. These may be melanomas.
Contact your usual healthcare provider or a dermatologist (a doctor with special training in skin diseases) if you notice anything on your skin that seems abnormal or suspicious to you.
Updated: March 2017
Posted: March 2012