An actinic keratosis is a rough, scaly patch on skin that develops from years of exposure to the sun. It’s most commonly found on the face, lips, ears, back of your hands, forearms, scalp or neck.
Also known as solar keratosis, an actinic keratosis enlarges slowly and usually causes no signs or symptoms other than a patch or small spot on your skin. These lesions take years to develop, usually first appearing in older adults.

Lentigines are due to localized proliferation of melanocytes. The most common type, solar lentigines, arise in middle age and also result from sun damage (age spots). They are most often found on the face and hands, and are larger and more defined than freckles.

The correct term for a single lesion is solar or actinic lentigo. These are common in those with fair skin but are also frequently seen in those who tan easily or have naturally dark skin.

Seborrheic keratosis is a common skin growth. It may look worrisome, but it is benign (not cancerous). These growths often appear in middle-aged and older adults. Sometimes the patient gets just one patch. It is, however, more common to have many but they are not contagious.

Most often,  seborrheic keratoses starts as small, rough bumps which then slowly,  thicken and get a warty surface. They can range in color from white to black but most are tan or brown.