Dermatoscope image of a seborrheic keratosis that has formed at the site of an intradermal naevus. Hairpin (u-shaped) blood vessels are seen within the lesion. A seborrheic keratosis is a skin growth, also known as a seborrheic wart, that is caused by overproduction of keratin, the tough fibrous protein found in hair and the outer layer of skin. Keratoses range from flat, dark brown rough patches, to small, wart-like protrusions covered with a greasy, removable crust. They are mainly found on the trunk and usually occur in elderly patients. They are harmless, but as they are unsightly can be removed by cryosurgery (destruction of tissue using extreme cold) or surgical excision. An intradermal naevus is a benign skin growth. It forms at the junction of the epidermis and the dermis, two of the skin's layers. |