Seborrheic keratoses are noncancerous benign skin growths that some people develop as they age. They often appear on the back or chest, but can occur on any part of the body. Seborrheic keratoses grow slowly, in groups or singly. Most people will develop at least one seborrheic keratosis during their lifetime.
Seborrheic keratoses are raised growths on the skin. Seborrheic means greasy and keratosis means thickening of the skin. There may be just one or clusters of dozens. They are usually started off light tan, and then may darken to dark brown or nearly black case reports are 13% and 36% exposed areas were more often flat and more than 3 mm in diameter than those on the non-exposed areas.
Clothing rubbing against can get them irritated and make them grow. Alpha-hydroxy lotions and mild topical steroid creams may help this. If they get very itchy, irritated and bleed easily they should be removed. When a seborrheic keratosis turns black it may be difficult to distinguish from a skin cancer without a biopsy.