Seborrheic keratoses (SKs) are extremely common benign neoplasms of the epidermis that typically appear on the chest and the back. There can be few or hundreds of these raised, "stuck-on"-appearing papules and plaques with well-defined borders. The etiology is unknown, although there is a familial trait for the development of multiple SKs with an autosomal dominant mode of inheritance. SKs tend to increase in incidence and number with increasing age. They may start out as a flat wrinkled plaque with a "postage stamp" appearance (flat seborrheic keratosis). SKs are asymptomatic, but when irritated or traumatized, they may become pruritic or painful with associated redness or bleeding.
SKs may occur on the upper or lower eyelids. In this location they are usually asymptomatic; however, larger lesions may interfere with vision.
Dermatosis papulosa nigra is a term given to the papular seborrheic keratoses (most often seen as dark brown 1-3 mm papules) on the face of individuals with darker skin colors.
Relatively rapid onset of numerous SKs may be a cutaneous sign of internal malignancy. Multiple eruptive SKs in association with a visceral cancer is referred to as the sign of Leser-Trélat. The most common associated malignancy is adenocarcinoma of the gastrointestinal tract.
ICD10CM: L82.1 – Other seborrheic keratosis
SNOMEDCT: 25499005 – Seborrheic keratosis
Differential Diagnosis & Pitfalls
Melanoma – For any dark or atypical appearing pigmented lesion, the diagnosis of melanoma should be ruled out.
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.