Seborrheic keratoses are common, benign, persistent skin lesions whose clinical picture varies. Their etiology remains unknown, but the effects of solar radiation, human papillomaviruses (HPV) and genetic factors have been implicated.

Seborrheic hyperkeratosis rarely occurs before the age of 30 years. Both sexes are equally affected. They grow more often in the face and upper trunk but can also appear at the extremities. The number of lesions varies. Most people experience fewer than 20 lesions, and in some cases there are numerous facial, trunk and extremity lesions. The lesions increase in number and size with age. Depending on the location, they can easily show irritation due to friction or injury.

Patients often wish to remove lesions for aesthetic reasons. Seborrheic hyperkeratosis responds perfectly to the CO2 laser, which is the treatment of choice. However, when there is the slightest suspicion that the lesion may be dysplastic nevus or melanoma, it must be surgically removed and sent for histological examination.