Seborrheic keratosis (seb-o-REE-ik ker-uh-TOE-sis) is one of the most common noncancerous skin growths in older adults.

A seborrheic keratosis usually appears as a brown, black or light tan growth on the face, chest, shoulders or back. The growth has a waxy, scaly, slightly elevated appearance. Occasionally, it appears singly, but multiple growths are more common. Seborrheic keratoses don't become cancerous, but they can look like skin cancer.

Seborrheic keratoses are normally painless and require no treatment. You may decide, however, to have them removed if they become irritated by clothing or for cosmetic reasons.

Source: http://www.mayoclinic.com

A seborrheic keratosis usually has the appearance of a waxy or wart-like growth. It typically appears on the face, chest, shoulders or back of the body. A seborrheic keratosis:

• Ranges in color, usually from light tan to brown or black
• Is round or oval shaped
• Has a characteristic "pasted on" look
• Is flat or slightly elevated with a scaly surface
• Ranges in size from very small to more than 1 inch (2.5 centimeters) across
• May itch

You may develop a single growth or cluster of growths. Though not painful, seborrheic keratoses may prove bothersome depending on their size and location. Be careful not to rub, scratch or pick them. This can lead to inflammation, bleeding and, in rare cases, infection.

When to see a doctor

See your doctor if:

• Many growths develop over a short time of a few weeks to months. Normally, seborrheic keratoses appear one or two at a time over many years.
• The growths get irritated or bleed when your clothing rubs against them. You may want the growths removed.
• You notice suspicious changes in your skin, such as sores or growths that grow rapidly, bleed and don't heal. These could be signs of skin cancer.

Source: http://www.mayoclinic.com

The exact cause of seborrheic keratoses isn't known. They are very common and generally increase in number with age. They tend to run in some families, so inheritance may play a role.

Source: http://www.mayoclinic.com

Your doctor can usually diagnose seborrheic keratosis by inspecting the growth. If the diagnosis is uncertain, particularly if the lesion might be cancer, your doctor might recommend removal so the tissue can be examined under a microscope.

Source: http://www.mayoclinic.com

Although anyone can develop seborrheic keratoses, you may be more likely to develop the condition if you are older than 40 and have a family history of seborrheic keratosis.

Source: http://www.mayoclinic.com