Table of ContentsView AllTable of ContentsWhat They AreCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
What They Are
Causes
Diagnosis
Treatment
Skin barnacles, medically known asseborrheic keratoses, are wart-like growths that may appear anywhere on the skin except for the palms and soles. These growths are harmless, but you may want to have them removed for aesthetic reasons or because they are a source of irritation.
This article looks at seborrheic keratoses, what they are, and how they are diagnosed and treated.
Some call seborrheic keratosis growths “the barnacles of aging,” as they’re most common after age 50.
What Are Skin Barnacles?
Seborrheic keratoses are harmless, noncancerous growths that usually appear during adulthood. These growths can vary in appearance but typically:
Because only the top skin layer is involved, seborrheic keratosis often has a “pasted-on” appearance, similar to a barnacle. The number of growths typically increases as you age.
Seborrheic keratoses are not painful but may itch, especially as you get older.If scratched or picked at, the growths can become irritated.
Skin barnacles don’t usually need to be treated, but some people have them removed for aesthetic purposes or because they can become irritated or get caught on clothes and jewelry.
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This photo contains content that some people may find graphic or disturbing.See PhotoDermNet /CC BY-NC-ND
This photo contains content that some people may find graphic or disturbing.See Photo
This photo contains content that some people may find graphic or disturbing.
DermNet /CC BY-NC-ND
Presence of Other Symptoms
While seborrheic keratosis is considered a benign skin condition, in rare cases, skin cancer (e.g., squamous cell carcinoma or basal cell carcinoma) can arise from cells that are contained within a seborrheic keratosis.
Research suggests that people with a suppressed immune system may have an increased risk of this phenomenon, which is called a malignant orcancerous transformation of a seborrheic keratosis.
Skin Cancer
What Causes Skin Barnacles?
The precise cause of seborrheic keratosis remains unknown. Experts believe genes play a role, as these growths tend to run in families.Other factors that may increase your chances of developing them include:
However, in some instances, if the growth looks suspicious for skin cancer or there’s any doubt about what they are, a skin biopsy can confirm a diagnosis.
Seborrheic keratosis can be mistaken for:CommonwartPrecancerous lesion calledactinic keratosis
Seborrheic keratosis can be mistaken for:
This photo contains content that some people may find graphic or disturbing.See PhotoViral warts on hand.DermNet /CC BY-NC-ND
This photo contains content that some people may find graphic or disturbing.See PhotoActinic keratosis.DermNet /CC BY-NC-ND
The different types of skin biopsies that may be performed include:
A pathologist then examines the skin samples under a microscope. If they find cancer cells, you’ll need additional testing to determine the stage of the cancer, which will guide treatment.
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Seborrheic keratosis doesn’t typically need treatment unless you consider it cosmetically undesirable, it’s uncomfortably itchy, or it’s easily irritated.
The good news is that there are several differenttreatment optionsavailable:
Research suggests that laser therapy is a better alternative than cryotherapy, as it’s less likely to cause hyperpigmentation (when removal of the growth causes darkening of the skin).
Summary
Seborrheic keratoses are also called “skin barnacles.” They tend to form during adulthood and are typically brown in color with a “stuck-on” appearance. These lesions are usually harmless, but you may want to have them removed for aesthetic reasons.
Because skin barnacles can sometimes look suspicious, your dermatologist may want to perform a biopsy to make sure the lesion is not cancerous.
If you decide to have your seborrheic keratosis removed, your dermatologist can use a number of techniques, including cryotherapy, a chemical peel, or laser treatment.
A Word From VerywellOne of the most common spots on the skin that begin to appear after age 50 are seborrheic keratoses. These are benign lesions, thought to be genetically related, that may be related to sun exposure. Rarely skin cancers can arise on them. There are many methods of removing them from freezing to laser ablation. It is always wise to see a dermatologist to have them checked and discuss treatment options and to get a yearly check with your dermatologist once lesions start to appear.—WILLIAM TRUSWELL, MD, MEDICAL EXPERT BOARD
A Word From Verywell
One of the most common spots on the skin that begin to appear after age 50 are seborrheic keratoses. These are benign lesions, thought to be genetically related, that may be related to sun exposure. Rarely skin cancers can arise on them. There are many methods of removing them from freezing to laser ablation. It is always wise to see a dermatologist to have them checked and discuss treatment options and to get a yearly check with your dermatologist once lesions start to appear.—WILLIAM TRUSWELL, MD, MEDICAL EXPERT BOARD
One of the most common spots on the skin that begin to appear after age 50 are seborrheic keratoses. These are benign lesions, thought to be genetically related, that may be related to sun exposure. Rarely skin cancers can arise on them. There are many methods of removing them from freezing to laser ablation. It is always wise to see a dermatologist to have them checked and discuss treatment options and to get a yearly check with your dermatologist once lesions start to appear.
—WILLIAM TRUSWELL, MD, MEDICAL EXPERT BOARD
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Braun RP, Ludwig S, Marghoob AA.Differential diagnosis of seborrheic keratosis: clinical and dermoscopic features.J Drugs Dermatol: JDD. 2017;16(9):835-42.American Academy of Dermatology Association.Seborrheic keratoses: overview.American Academy of Dermatology Association.Seborrheic keratoses: signs and symptoms.Conic RZ, Napekoski K, Schuetz H, Piliang M, Bergfeld W, Atanaskova Mesinkovska N.The role of immunosuppression in squamous cell carcinomas arising in seborrheic keratosis.J Am Acad Dermatol. 2017;76(6):1146-1150. doi:10.1016/j.jaad.2016.12.002Cimpean I, Theate I, Vanhooteghem O.Seborrheic keratosis evolution into squamous cell carcinoma: a truly modified sun-related tumor? A case report and review of the literature.Dermatol Reports. 2019;11(1):7999. doi:10.4081/dr.2019.7999American Academy of Dermatology Association.Seborrheic keratoses: who gets and causes.Del Rosso JQ.A closer look at seborrheic keratoses: patient perspectives, clinical relevance, medical necessity, and implications for management.J Clin Aesthet Dermatol. 2017;10(3):16-25.Wollina U.Seborrheic keratoses - the most common benign skin tumor of humans. Clinical presentation and an update on pathogenesis and treatment options.Open Access Maced J Med Sci. 2018;6(11):2270-2275. doi:10.3889/oamjms.2018.460Gurel MS, Aral BB.Effectiveness of erbium: YAG laser and cryosurgery in seborrheic keratoses: Randomized, prospective intraindividual comparison study.J Dermatolog Treat.2015;26(5):477-80. doi:10.3109/09546634.2015.1024597Additional ReadingBedir R, Yurdakul C, Gucer H, Sehitoglu I.Basal cell carcinoma arising within seborrheic keratosis.J Clin Diagn Res. 2014;8(7):YD06-YD07. doi:10.7860/JCDR/2014/8665.4604Boyd A, Su P, Shyr Y, et al.Squamous cell carcinomas in situ arising in seborrheic keratoses: an association with concomitant immunosuppression?Int J Dermatol.2014;53(11):1346-50. doi:10.1111/ijd.12086
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Braun RP, Ludwig S, Marghoob AA.Differential diagnosis of seborrheic keratosis: clinical and dermoscopic features.J Drugs Dermatol: JDD. 2017;16(9):835-42.American Academy of Dermatology Association.Seborrheic keratoses: overview.American Academy of Dermatology Association.Seborrheic keratoses: signs and symptoms.Conic RZ, Napekoski K, Schuetz H, Piliang M, Bergfeld W, Atanaskova Mesinkovska N.The role of immunosuppression in squamous cell carcinomas arising in seborrheic keratosis.J Am Acad Dermatol. 2017;76(6):1146-1150. doi:10.1016/j.jaad.2016.12.002Cimpean I, Theate I, Vanhooteghem O.Seborrheic keratosis evolution into squamous cell carcinoma: a truly modified sun-related tumor? A case report and review of the literature.Dermatol Reports. 2019;11(1):7999. doi:10.4081/dr.2019.7999American Academy of Dermatology Association.Seborrheic keratoses: who gets and causes.Del Rosso JQ.A closer look at seborrheic keratoses: patient perspectives, clinical relevance, medical necessity, and implications for management.J Clin Aesthet Dermatol. 2017;10(3):16-25.Wollina U.Seborrheic keratoses - the most common benign skin tumor of humans. Clinical presentation and an update on pathogenesis and treatment options.Open Access Maced J Med Sci. 2018;6(11):2270-2275. doi:10.3889/oamjms.2018.460Gurel MS, Aral BB.Effectiveness of erbium: YAG laser and cryosurgery in seborrheic keratoses: Randomized, prospective intraindividual comparison study.J Dermatolog Treat.2015;26(5):477-80. doi:10.3109/09546634.2015.1024597Additional ReadingBedir R, Yurdakul C, Gucer H, Sehitoglu I.Basal cell carcinoma arising within seborrheic keratosis.J Clin Diagn Res. 2014;8(7):YD06-YD07. doi:10.7860/JCDR/2014/8665.4604Boyd A, Su P, Shyr Y, et al.Squamous cell carcinomas in situ arising in seborrheic keratoses: an association with concomitant immunosuppression?Int J Dermatol.2014;53(11):1346-50. doi:10.1111/ijd.12086
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Braun RP, Ludwig S, Marghoob AA.Differential diagnosis of seborrheic keratosis: clinical and dermoscopic features.J Drugs Dermatol: JDD. 2017;16(9):835-42.American Academy of Dermatology Association.Seborrheic keratoses: overview.American Academy of Dermatology Association.Seborrheic keratoses: signs and symptoms.Conic RZ, Napekoski K, Schuetz H, Piliang M, Bergfeld W, Atanaskova Mesinkovska N.The role of immunosuppression in squamous cell carcinomas arising in seborrheic keratosis.J Am Acad Dermatol. 2017;76(6):1146-1150. doi:10.1016/j.jaad.2016.12.002Cimpean I, Theate I, Vanhooteghem O.Seborrheic keratosis evolution into squamous cell carcinoma: a truly modified sun-related tumor? A case report and review of the literature.Dermatol Reports. 2019;11(1):7999. doi:10.4081/dr.2019.7999American Academy of Dermatology Association.Seborrheic keratoses: who gets and causes.Del Rosso JQ.A closer look at seborrheic keratoses: patient perspectives, clinical relevance, medical necessity, and implications for management.J Clin Aesthet Dermatol. 2017;10(3):16-25.Wollina U.Seborrheic keratoses - the most common benign skin tumor of humans. Clinical presentation and an update on pathogenesis and treatment options.Open Access Maced J Med Sci. 2018;6(11):2270-2275. doi:10.3889/oamjms.2018.460Gurel MS, Aral BB.Effectiveness of erbium: YAG laser and cryosurgery in seborrheic keratoses: Randomized, prospective intraindividual comparison study.J Dermatolog Treat.2015;26(5):477-80. doi:10.3109/09546634.2015.1024597
Braun RP, Ludwig S, Marghoob AA.Differential diagnosis of seborrheic keratosis: clinical and dermoscopic features.J Drugs Dermatol: JDD. 2017;16(9):835-42.
American Academy of Dermatology Association.Seborrheic keratoses: overview.
American Academy of Dermatology Association.Seborrheic keratoses: signs and symptoms.
Conic RZ, Napekoski K, Schuetz H, Piliang M, Bergfeld W, Atanaskova Mesinkovska N.The role of immunosuppression in squamous cell carcinomas arising in seborrheic keratosis.J Am Acad Dermatol. 2017;76(6):1146-1150. doi:10.1016/j.jaad.2016.12.002
Cimpean I, Theate I, Vanhooteghem O.Seborrheic keratosis evolution into squamous cell carcinoma: a truly modified sun-related tumor? A case report and review of the literature.Dermatol Reports. 2019;11(1):7999. doi:10.4081/dr.2019.7999
American Academy of Dermatology Association.Seborrheic keratoses: who gets and causes.
Del Rosso JQ.A closer look at seborrheic keratoses: patient perspectives, clinical relevance, medical necessity, and implications for management.J Clin Aesthet Dermatol. 2017;10(3):16-25.
Wollina U.Seborrheic keratoses - the most common benign skin tumor of humans. Clinical presentation and an update on pathogenesis and treatment options.Open Access Maced J Med Sci. 2018;6(11):2270-2275. doi:10.3889/oamjms.2018.460
Gurel MS, Aral BB.Effectiveness of erbium: YAG laser and cryosurgery in seborrheic keratoses: Randomized, prospective intraindividual comparison study.J Dermatolog Treat.2015;26(5):477-80. doi:10.3109/09546634.2015.1024597
Bedir R, Yurdakul C, Gucer H, Sehitoglu I.Basal cell carcinoma arising within seborrheic keratosis.J Clin Diagn Res. 2014;8(7):YD06-YD07. doi:10.7860/JCDR/2014/8665.4604Boyd A, Su P, Shyr Y, et al.Squamous cell carcinomas in situ arising in seborrheic keratoses: an association with concomitant immunosuppression?Int J Dermatol.2014;53(11):1346-50. doi:10.1111/ijd.12086
Bedir R, Yurdakul C, Gucer H, Sehitoglu I.Basal cell carcinoma arising within seborrheic keratosis.J Clin Diagn Res. 2014;8(7):YD06-YD07. doi:10.7860/JCDR/2014/8665.4604
Boyd A, Su P, Shyr Y, et al.Squamous cell carcinomas in situ arising in seborrheic keratoses: an association with concomitant immunosuppression?Int J Dermatol.2014;53(11):1346-50. doi:10.1111/ijd.12086
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