Seborrheic keratoses are very common harmless skin lesions that appear during adult life. The cause of seborrheic keratoses is not known, however is generally regarded to be related to aging and maturity of the skin. They become more numerous with time and some people inherit a tendency to develop a very large number of them.
Seborrheic keratoses begin as slightly raised, brown spots anywhere on the skin. Gradually they thicken and develop a rough, warty surface. They slowly darken and may turn black. They appear to stick on to the skin like barnacles.
Some skin cancers are sometimes difficult to tell apart from seborrheic keratoses, so if you are concerned or unsure about any skin lesion consult your dermatologist. Seborrheic keratoses can be easily removed. Occasionally, they can become unsightly, itch or rub against your clothes. Methods used to remove seborrheic keratoses include liquid nitrogen, curettage, laser surgery and shave biopsy.