Seborrheic keratoses are common, multiple, benign tumors of the skin.
They usually appear in the fourth and fifth decades of life and their prevalence increases with age and sun exposure.
They appear as well-circumscribed "stuck-on" plaques or papules and may look like warts.
They are usually asymptomatic but can become irritated and inflamed spontaneously or because of friction from clothing.
Treatment is not necessary because of their benign nature, but if irritated, itching, and displeasing, can be initially treated with cryotherapy and curettage.
Most important differential diagnosis, and of patient concern, is malignant melanoma.
Seborrheic keratosis is a common, benign skin tumor most commonly found on the torso and forehead. The lesions clinically appear in multiples as well-circumscribed gray-brown-to-black plaques with a "stuck-on" appearance. Later the plaques can become raised and may show a verrucous surface. Most lesions do not exceed 1 cm in diameter. The lesions are normally painless and require no treatment.
History and exam
Key diagnostic factors
- lesions appear "stuck-on
- localization on torso or face
- yellow or light- to dark-brown-colored lesions
- slightly raised, flat surface lesions
- wart-like texture
- multiple lesions
- itching (prurigo)
Other diagnostic factors
- round yellow-white horn pearls in the surface of lesions
- age over 50 years
- Fitzpatrick skin type I or II
- Fitzpatrick skin type IV, V, or VI (dermatosis papulosa nigra)
- female sex (dermatosis papulosa nigra)
- family history
- sun/UV exposure
Investigations to consider
- biopsy and histopathologic examination
- reflectance confocal microscopy (RCM)
irritated or itching lesions
raised seborrheic keratosis
flat seborrheic keratosis
Use of this content is subject to our disclaimer