Please Remove Adblock
Adverts are the main source of Revenue for DoveMed. Please remove adblock to help us create the best medical content found on the Internet.

Seborrheic Keratosis

Last updated Jan. 15, 2019

Approved by: Krish Tangella MD, MBA, FCAP


Microscopic pathology image of skin showing Seborrheic Keratosis. Keratin filled horn cysts are seen.

What are the other Names for this Condition? (Also known as/Synonyms)

  • Seborrheic Verruca
  • Senile Wart
  • Verruca Seborrhoica

What is Seborrheic Keratosis? (Definition/Background Information)

  • Seborrheic Keratosis is a very common, benign tumor of the sebaceous glands on skin that resembles a wart. They are associated with itching and may ulcerate and bleed due to intense scratching
  • Seborrheic Keratosis is generally observed in middle-aged adults, especially lighter-skinned individuals
  • The cause of development of the condition is unknown, though the risk factors for Seborrheic Keratosis include exposure to sun and ultraviolet (UV) light
  • This pigmented tumor resembles melanoma of skin (a malignant tumor of the skin) and are hence, frequently biopsied, to ensure a definitive diagnosis
  • A treatment of Seborrheic Keratosis may be undertaken, if they present cosmetic concerns to the individual. In such cases, a simple surgical excision is sufficient treatment. The prognosis is excellent on removal of the tumor

Who gets Seborrheic Keratosis? (Age and Sex Distribution)

  • Seborrheic Keratosis is commonly seen in middle-aged adults; the incidence increases with age
  • It is observed in both men and women, but the incidence is more in men
  • This condition is observed worldwide across all racial and ethnic groups; however, lighter-skinned individuals (especially Caucasians) are more prone to Seborrheic Keratosis than darker-skinned individuals (such as Asians, Africans, etc.)

What are the Risk Factors for Seborrheic Keratosis? (Predisposing Factors)

The risk factors for Seborrheic Keratosis include:

  • Exposure to sunlight and UV light
  • Skin tanning (use of tanning beds)
  • Caucasians are more vulnerable compared to other darker-toned individuals

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Seborrheic Keratosis? (Etiology)

  • The exact cause and development of Seborrheic Keratosis is unknown
  • But it seems to be influenced by exposure to sunlight
  • Even though these tumors resemble warts, they are not caused by a viral infection

What are the Signs and Symptoms of Seborrheic Keratosis?

In most cases, Seborrheic Keratosis does not present any signs and symptoms. However, the following may be noted:

  • They occur as single or multiple tiny skin overgrowths that may occur anywhere in the body
  • They are slow-growing tumors that may range in size from a few mm to up to 3 cm
  • Typically, Seborrheic Keratosis has a “stuck on the skin” appearance
  • The nodules are benign and no malignancy occurs in them, even though they may be confused with melanoma (a malignant skin tumor)
  • Seborrheic Keratosis is associated with itching, which can lead to constant scratching, a condition known as Irritated Seborrheic Keratosis. This can result in inflammation and bleeding

How is Seborrheic Keratosis Diagnosed?

A diagnosis of Seborrheic Keratosis may involve the following procedures and tests:

  • Complete physical examination with evaluation of medical history
  • Dermoscopy: It is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
  • Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
  • Skin biopsy: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

Note: The diagnosis of Seborrheic Keratosis may not necessarily involve a biopsy. However, if there is a suspicion of melanoma, then the healthcare provider may recommend a biopsy.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Seborrheic Keratosis?

No significant complications generally arise from Seborrheic Keratosis; however:

  • These wart-like growths may present cosmetic concerns, in which case a surgery may be proposed
  • If they are traumatized, severe pain and bleeding with ulceration may occur
  • Bleeding and ulceration can cause infection due to bacteria or fungi

How is Seborrheic Keratosis Treated?

Seborrheic Keratosis may not require any treatment in a majority of cases. However, in case they present cosmetic issues in the individual, they may be removed.

  • The healthcare provider may chose to regularly monitor the tumor, if they are asymptomatic. A ‘wait and watch’ approach may be adopted
  • A complete surgical excision can result in a cure
  • Follow-up care with regular screening and check-ups are important

How can Seborrheic Keratosis be Prevented?

  • Current medical research has not established a definitive way to prevent the formation of Seborrheic Keratosis
  • However, overexposure to sun’s rays and UV light must be avoided

What is the Prognosis of Seborrheic Keratosis? (Outcomes/Resolutions)

  • The prognosis of Seborrheic Keratosis is excellent on its complete excision and removal
  • Since, these are benign tumors, the prognosis is excellent, even if no treatment is provided and only periodic observation is maintained

Additional and Relevant Useful Information for Seborrheic Keratosis:

  • Seborrheic Keratosis is not an infectious condition; they do not spread from one individual to another
  • There is no definitive proof that consuming certain foods influence its development

What are some Useful Resources for Additional Information?

References and Information Sources used for the Article:

Helpful Peer-Reviewed Medical Articles:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: Nov. 19, 2015
Last updated: Jan. 15, 2019