The cause of seborrheic keratosis is unknown, but genetic mutations have been identified in certain types. The lesions commonly occur in middle age and later and most often appear on the trunk or temples. In darker-skinned people, multiple 1- to 3-mm lesions can occur on the cheekbones; this condition is termed dermatosis papulosa nigra.
Seborrheic keratoses vary in size and grow slowly. They may be round or oval and flesh-colored, brown, or black. They usually appear stuck on and may have a verrucous, velvety, waxy, scaling, or crusted surface.
Seborrheic keratoses that are large, multiple, and/or rapidly developing can be a cutaneous paraneoplastic syndrome Cutaneous paraneoplastic syndromes Paraneoplastic syndromes are symptoms that occur at sites distant from a tumor or its metastasis. Although the pathogenesis remains unclear, these symptoms may be secondary to substances secreted... read more 
(Leser-Trélat sign) in patients who have certain cancers (eg, lymphoma Overview of Lymphoma Lymphomas are a heterogeneous group of tumors arising in the reticuloendothelial and lymphatic systems. The major types are Hodgkin lymphoma Non-Hodgkin lymphoma See table Comparison of Hodgkin... read more , gastrointestinal cancer).
Seborrheic keratoses are benign pigmented lesions. Cause is unknown. They tend to develop in older people and have a stuck-on appearance with a verrucous, velvety, waxy, scaly, or crusted surface.
Image provided by Thomas Habif, MD.
This photo shows seborrheic keratoses (hyperpigmented lesions with a stuck-on appearance) on a patient's back.
DermPics/SCIENCE PHOTO LIBRARY
This photo shows multiple, small seborrheic keratoses on the cheekbones and forehead of a person with dark skin.
DermPics/SCIENCE PHOTO LIBRARY
Leser-Trélat sign is the rapid onset of numerous seborrheic keratoses (benign, often pigmented skin lesions with a "stuck-on" appearance).
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Diagnosis of Seborrheic Keratoses
Clinical evaluation
Diagnosis of seborrheic keratosis is clinical.
Treatment of Seborrheic Keratoses
Removal only if bothersome
Lesions are not premalignant and need no treatment unless they are irritated, itchy, or cosmetically bothersome.
Lesions may be removed with little or no scarring by cryotherapy (which can cause hypopigmentation) or by electrodesiccation and curettage after local injection of lidocaine.
Drugs Mentioned In This Article
| Drug Name | Select Trade |
|---|---|
lidocaine |
7T Lido, Akten , ALOCANE, ANASTIA, AneCream, Anestacon, Aspercreme with Lidocaine, Astero , BenGay, Blue Tube, Blue-Emu, CidalEaze, DermacinRx Lidogel, DermacinRx Lidorex, DERMALID, Ela-Max, GEN7T, Glydo, Gold Bond, LidaMantle, Lidocan, Lidocare, Lidoderm, LidoDose, LidoDose Pediatric, Lidofore, LidoHeal-90, LIDO-K , Lidomar , Lidomark, LidoReal-30, LidoRx, Lidosense 4 , Lidosense 5, Lidosol, LIDO-SORB, Lidotral, Lidovix L, LIDOZION, Lidozo, LMX 4, LMX 4 with Tegaderm, LMX 5, LTA, Lydexa, Moxicaine, Numbonex, ReadySharp Lidocaine, RectaSmoothe, RectiCare, Salonpas Lidocaine, Senatec, Solarcaine, SUN BURNT PLUS, Tranzarel, Xyliderm, Xylocaine, Xylocaine Dental, Xylocaine in Dextrose, Xylocaine MPF, Xylocaine Topical, Xylocaine Topical Jelly, Xylocaine Topical Solution, Xylocaine Viscous, Zilactin-L, Zingo, Zionodi, ZTlido |
