Background

Seborrheic keratoses are regular benign skin growths that typically appear in middle-aged or older individuals. They are non-cancerous and pose no significant health risks. Seborrheic keratoses are characterized by their waxy, scaly, or wart-like appearance and can vary in color from tan to brown or black. These growths can develop anywhere on the body but are most commonly found on the face, chest, shoulders, back, or abdomen. 

The exact cause of seborrheic keratoses is typically unknown, but several factors may contribute to their development. Genetic predisposition plays a role, as these growths tend to run in families. Hormonal changes, like those occurring during pregnancy or menopause, may also affect their appearance.

Sun exposure has been linked to the development of seborrheic keratoses, as they are more common in areas exposed to the sun. Additionally, advancing age is a significant risk factor, with the prevalence of seborrheic keratoses increasing. While seborrheic keratoses are typically harmless and do not require treatment, they may be cosmetically bothersome or mistaken for other skin conditions, leading individuals to seek removal for aesthetic reasons. 

Epidemiology

Seborrheic keratosis is a regular benign skin tumor that primarily affects adult and elderly individuals. It is prevalent throughout middle-aged and elderly populations.  

Seborrheic keratosis lesions are one of the most common types of skin lesions, with a prevalence of approximately 83 million Americans affected. They typically appear gradually and are characterized by round or oval-shaped patches on the skin with a “stuck on” appearance.  

The exact etiology of seborrheic keratosis is not fully understood, but it is thought to result from a clonal expansion of mutated epidermal keratinocytes. There may be a link between extrinsic skin aging and the occurrence of seborrheic keratosis. The prevalence of seborrheic keratosis increases with age.

A study conducted on young Australians aged 15 to 30 years found a prevalence of seborrheic keratosis of 23.5% in the study population. The prevalence increased with age, ranging from 15.7% in 15- to 19-year-olds to 32.3% in those aged 25 to 30 years. Seborrheic keratoses are generally benign and do not require treatment unless they become symptomatic or cause cosmetic concerns.  

Anatomy

Pathophysiology

The exact pathophysiology of seborrheic keratoses has yet to be fully understood, but several mechanisms have been proposed to explain their development. One theory suggests that seborrheic keratoses arise from the proliferation of epidermal cells, specifically keratinocytes. These cells undergo hyperproliferation and abnormal differentiation, forming thickened, scaly, and pigmented lesions.

This cellular dysregulation’s underlying cause is unknown, but genetic factors likely play a role, as seborrheic keratoses tend to run in families. Another proposed mechanism involves alterations in the signaling pathways that regulate cell growth and differentiation. The activation of specific signaling pathways, such as the mitogen-activated protein kinase pathway, has been observed in seborrheic keratoses. Abnormal activation of these pathways can lead to uncontrolled cell growth and the formation of characteristic skin lesions. 

In addition to genetic and signaling pathway abnormalities, other factors may contribute to the pathophysiology of seborrheic keratoses. Chronic sun exposure has been associated with the development of these growths, suggesting that ultraviolet radiation may play a role in their pathogenesis. Hormonal factors, such as changes in estrogen levels during pregnancy or menopause, may also influence the development of seborrheic keratoses. 

Etiology

The etiology of seborrheic keratoses, or the underlying causes of their development, has yet to be fully understood.  

• Genetic Factors: Evidence suggests a genetic predisposition to seborrheic keratoses. The condition tends to run in families, and specific gene mutations or variations may increase the likelihood of developing these growths. However, specific genes associated with seborrheic keratoses have not been identified. 
• Age: Seborrheic keratoses are more common in older individuals, increasing their prevalence. It is believed that cumulative exposure to various risk factors and age-related skin changes may contribute to their development. 
• Sun Exposure: Chronic and prolonged exposure is associated with seborrheic keratoses. Ultraviolet radiation from the sun rays may damage the skin cells and disrupt their average growth and differentiation, potentially leading to the formation of these lesions. Seborrheic keratoses are commonly found on sun-exposed body areas, such as the face, neck, and shoulders. 
• Hormonal Factors: Hormonal changes, such as those occurring during pregnancy or menopause, may influence the development of seborrheic keratoses. Fluctuations in estrogen levels have been suggested to play a role in the growth and appearance of these lesions. Seborrheic keratoses may also become more numerous or enlarge during pregnancy. 
• Other Factors: Other factors proposed to contribute to seborrheic keratoses include obesity, immune system dysfunction, and certain medical conditions such as human papillomavirus (HPV) infection. However, the exact relationship between these factors and the development of seborrheic keratoses is still being investigated. 

Genetics

Prognostic Factors

Seborrheic keratoses are generally considered benign and do not pose significant health risks. They are typically non-cancerous and have an excellent prognosis.  

• Size and Location: Larger seborrheic keratoses or those located in areas prone to irritation or friction, such as the groin or under the breasts, maybe more symptomatic or bothersome. They can cause discomfort, itchiness, or cosmetic concerns. In such cases, medical intervention may be sought for removal or management. 
• Rapid Growth or Change: Seborrheic keratoses generally have a slow growth rate and remain stable over time. However, if a seborrheic keratosis exhibits rapid growth or undergoes significant changes in appearance, it may warrant further evaluation. Sudden changes can indicate an underlying condition or potential transformation into a more concerning skin lesion, such as melanoma. A dermatological assessment is necessary in such cases. 
• Concurrent Skin Conditions: Other skin conditions, such as actinic keratoses (pre-cancerous lesions) or skin cancers, alongside seborrheic keratoses, may impact the prognosis. Proper diagnosis and examination is crucial to differentiate seborrheic keratoses from other potentially more worrisome skin lesions. 
• Patient Concerns: The prognosis of seborrheic keratoses may also be influenced by patient-specific factors, such as cosmetic preferences and psychological impact. Seborrheic keratoses can be unsightly or cause emotional distress due to their appearance. In such cases, removal options may be pursued for aesthetic reasons, even though it does not alter the overall prognosis of the condition. 

Clinical History

Clinical Presentation of Seborrheic keratoses can vary depending on factors such as age group, associated comorbidity or activity, and the acuity of presentation.  

Age group:  

Seborrheic keratoses are more commonly seen in middle-aged and older individuals, typically appearing after age 40. However, they can occur at any age. 

Physical Examination

Seborrheic keratoses can be identified during a physical examination based on their characteristic appearance and location.  

• Observation: The healthcare provider will visually inspect the skin for seborrheic keratoses. These lesions typically appear as raised, well-defined, and round or oval-shaped growths on the skin.  
• Color and Texture: Seborrheic keratoses often exhibit a range of colors, including tan, brown, black, or sometimes even shades of yellow or white. The lesions can have a waxy, scaly, or rough texture and may appear “stuck on” to the skin. They can have a slightly elevated or flat surface. 
• Distribution: Seborrheic keratoses commonly occur on sun-exposed body areas, such as the face, neck, chest, shoulders, back, and abdomen. However, they can also appear in non-exposed areas, such as the scalp, groin, or under the breasts. The healthcare provider will examine exposed and non-exposed areas to assess the distribution of lesions. 
• Number and Size: The number of seborrheic keratoses can vary from a few to numerous lesions. The size of individual lesions can range from small millimeters to larger centimeters. The healthcare provider will evaluate the number and size of lesions to determine the extent of involvement. 
• Associated Symptoms: Seborrheic keratoses are generally asymptomatic, but they can occasionally cause itching, irritation, or tenderness, particularly if they are subjected to friction or rubbing against clothing or jewelry. The healthcare provider will assess if there are any associated symptoms or signs of inflammation. 
• Differential Diagnosis: It is crucial to differentiate seborrheic keratoses from other skin conditions, such as melanoma, basal cell carcinoma, or actinic keratoses. The healthcare provider will carefully examine the lesions and consider other clinical features to rule out any concerning or potentially malignant skin lesions. 

Age group

Associated comorbidity

Seborrheic keratoses can be seen in individuals with various comorbidities or activities, but they are not directly associated with any specific condition. They are generally unrelated to systemic illnesses or underlying diseases. 

Associated activity

Acuity of presentation

Seborrheic keratoses usually have a slow and gradual onset, with lesions developing over months or years. They typically appear as raised, well-defined, and sharply demarcated growths on the skin.

The color of the lesions can vary, ranging from tan to brown or black. They often have a waxy or stuck-on appearance and may resemble a wart or a piece of cake. Seborrheic keratoses are usually asymptomatic but can occasionally become itchy, irritated, or tender due to friction or rubbing against clothing or jewelry. 

Differential Diagnoses

When evaluating a patient with skin lesions, several conditions may be considered in the differential diagnosis of seborrheic keratoses.  

• Melanocytic Lesions: Melanocytic lesions can mimic seborrheic keratoses, including melanoma and atypical nevi (moles). These lesions may have irregular borders, asymmetry, variable colors, or exhibit changes over time.  
• Dermatosis Papulosa Nigra (DPN): DPN is a benign skin condition characterized by small, smooth, brown to black papules typically found on the face and neck, especially in individuals with darker skin types.  
• Actinic Keratoses (AK): AKs are precancerous skin lesions caused by sun damage. They typically present as rough, scaly patches or plaques on sun-exposed areas.  
• Epidermal Nevi: Epidermal nevi are benign overgrowths of the epidermis that can appear in various forms, such as verrucous, linear, or sebaceous nevi.  
• Verruca Vulgaris (Common Warts): Common warts are caused by human papillomavirus (HPV) infection and resemble seborrheic keratoses, particularly if they have a rough, keratotic surface.  
• Other Benign Skin Lesions: Other benign skin growths, such as skin tags (acrochordons), cherry angiomas, and dermatofibromas, may also have similarities to seborrheic keratoses in terms of appearance.  

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

The treatment paradigm for seborrheic keratoses depends on various factors such as the location, size, number of lesions, patient preference, and the presence of symptoms. In most cases, seborrheic keratoses do not require treatment as they are benign and do not pose a significant health risk. However, treatment options are available for symptomatic or cosmetically bothersome lesions. 

The primary treatment approach for seborrheic keratoses involves their removal or destruction. This can be achieved through several methods, including cryotherapy (freezing with liquid nitrogen), curettage (scraping off the lesion), electrocautery (burning with an electric current), laser therapy, or application of topical agents such as trichloroacetic acid.

These procedures are generally safe and well-tolerated, with minimal scarring and low risk of complications. However, it’s important to note that removing seborrheic keratoses is typically considered an elective procedure for cosmetic reasons and should be discussed with a healthcare professional. 

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

use-of-the-non-pharmacological-therapy-for-modifying-the-environment

Seborrheic keratoses are typically not influenced by environmental modifications. Genetic factors and age-related changes in the skin primarily determine these skin growths.

However, certain environmental factors, such as sun exposure, can contribute to developing or worsening seborrheic keratoses.

While environmental modifications may not directly treat seborrheic keratoses, they can help prevent their progression or the formation of new lesions.  

• Sun Protection: Protecting the skin from excessive sun exposure can help minimize the development or worsening of seborrheic keratoses. This includes wearing a broad-spectrum sunscreen with a high SPF, seeking shade during peak sun hours, and wearing protective clothing outdoors, such as hats and long sleeves. 
• Avoidance of Irritation: Avoiding activities or situations that may cause friction or irritation to existing seborrheic keratoses can help prevent symptoms like itching or discomfort. For example, wearing loose-fitting clothing and avoiding tight accessories or jewelry that rub against the lesions can reduce irritation. 
• Gentle Skin Care: Maintaining a gentle skincare routine can help minimize irritation and potential inflammation of seborrheic keratoses. Use mild cleansers and avoid harsh or abrasive products that can aggravate the skin. 
• Regular Skin Examinations: Performing regular self-skin examinations and seeking medical attention for any new or changing skin lesions can help ensure early detection and appropriate management of seborrheic keratoses or any other concerning skin conditions. 

Use of cryotherapy or cryosurgery in managing seborrheic keratoses

Seborrheic keratoses are benign skin growths that are typically brown, black, or tan in color. While cryotherapy, which involves freezing the growths with liquid nitrogen, is commonly used to remove various skin lesions, it is not typically considered the first-line treatment for seborrheic keratoses. However, it may be utilized in certain cases where the growths are causing discomfort or cosmetic concerns. 

• Procedure: Cryotherapy involves applying liquid nitrogen to the seborrheic keratosis growths, causing them to freeze and eventually fall off. The treatment is performed in a doctor’s office and usually does not require anesthesia. 
• Efficacy: Cryotherapy can effectively remove seborrheic keratoses; however, it may not completely eliminate all lesions in a single treatment. Additional sessions may be necessary. 
• Side Effects: Cryotherapy may cause temporary side effects such as pain, blistering, redness, and swelling at the treatment site.  
• Suitability: Cryotherapy is generally more suitable for smaller seborrheic keratoses, particularly those located in easily accessible areas. Larger or thickened growths may not respond as well to cryotherapy. 

Use of Curettage or shave excision in managing Seborrheic keratoses

Curettage or shave excision is a common and effective method for managing seborrheic keratoses. It involves the physical removal of the growth using a sharp instrument, such as a curette or a scalpel.  

• Procedure: Curettage or shave excision is typically performed in a dermatologist’s office or clinic. The area surrounding the seborrheic keratosis is numbed using a local anesthetic, and then the growth is gently scraped or shaved off using a specialized instrument. 
• Efficacy: Curettage or shave excision is generally effective in removing seborrheic keratoses. The procedure allows the dermatologist to precisely target and remove the growth, and it is often used for larger or thicker lesions. 
• Healing process: After the procedure, a scab will form at the treatment site, which will eventually fall off as the area heals. It’s important to follow any post-procedure care instructions provided by your dermatologist, such as keeping the area clean and applying an ointment or dressing as recommended. 
• Side effects: Common side effects of curettage or shave excision may include temporary discomfort, redness, and mild bleeding at the treatment site. In some cases, the area may take a few weeks to fully heal, and there is a possibility of scarring, though it is generally minimal. 
• Suitability: Curettage or shave excision is suitable for seborrheic keratoses located on the surface of the skin. However, it may not be appropriate for lesions that are suspicious for malignancy or those located in sensitive areas, such as the eyelids or genitals. In such cases, a biopsy or alternative treatment method may be recommended. 

Use of Electrodesiccation in managing Seborrheic keratoses

Electrodesiccation is another commonly used method for managing seborrheic keratoses. It involves using an electric current to burn and destroy the growth.  

• Procedure: Electrodesiccation is typically performed in a dermatologist’s office or clinic. The area surrounding the seborrheic keratosis is numbed using a local anesthetic, and then a specialized instrument with an electric current is used to burn and destroy the growth. 
• Efficacy: Electrodesiccation is generally effective in removing seborrheic keratoses. The procedure allows the dermatologist to precisely target and destroy the growth, and it is often used for thicker or more resistant lesions. 
• Healing process: After the procedure, a scab will form at the treatment site, which will eventually fall off as the area heals. It’s important to follow any post-procedure care instructions provided by your dermatologist, such as keeping the area clean and applying an ointment or dressing as recommended. 
• Side effects: Common side effects of electrodesiccation may include temporary discomfort, redness, and mild bleeding at the treatment site. In some cases, the area may take a few weeks to fully heal, and there is a possibility of scarring, though it is generally minimal. 
• Suitability: Electrodesiccation is suitable for seborrheic keratoses located on the surface of the skin. However, it may not be appropriate for lesions that are suspicious for malignancy or those located in sensitive areas. In such cases, a biopsy or alternative treatment method may be recommended. 

use-of-intervention-with-a-procedure-in-treating-seborrheic-keratoses

One of the standard treatment interventions for seborrheic keratoses is their removal or destruction through a procedure. Several procedures can effectively remove seborrheic keratoses.  

• Cryotherapy: Cryotherapy involves freezing the seborrheic keratosis with liquid nitrogen. The frigid temperature destroys the lesion, causing it to fall off. Cryotherapy is a quick and straightforward procedure, but it may cause temporary redness, swelling, and blistering in the treated area. 
• Curettage: Curettage is a procedure in which the seborrheic keratosis is scraped off using a specialized instrument called a curette. Local anesthesia may be applied to numb the area before the procedure. Curettage may be followed by electrocautery to control bleeding and promote healing. 
• Electrocautery: Electrocautery uses heat from an electric current to burn off the seborrheic keratosis. The procedure involves directly applying a heated needle or wire to the lesion, effectively destroying it. Local anesthesia may be administered to minimize discomfort during the procedure. 
• Laser Therapy: Laser therapy utilizes a focused beam of light to target and remove seborrheic keratoses. The laser energy selectively destroys the lesion while minimizing damage to the surrounding skin.  
• Topical Agents: In some cases, topical agents such as trichloroacetic acid (TCA) or other chemical peels may be applied to the seborrheic keratosis to destroy the lesion chemically. These agents cause controlled chemical exfoliation and subsequent removal of the lesion. 

use-of-phases-in-managing-seborrheic-keratoses

The treatment phase of management for seborrheic keratoses involves addressing symptomatic or cosmetically bothersome lesions through various treatment interventions.  

• Assessment and Diagnosis: The first step in the treatment phase is the assessment and diagnosis of seborrheic keratoses. A healthcare professional, typically a dermatologist, will evaluate the lesions to confirm the diagnosis and rule out any other concerning skin conditions. They will consider the location, size, number, and appearance of the lesions, as well as the patient’s concerns and symptoms. 
• Treatment Decision: Based on the assessment, the healthcare professional will discuss the available treatment options with the patient. The decision regarding treatment will consider factors such as the patient’s preference, the location and characteristics of the lesions, and any associated symptoms or complications. The healthcare professional will explain the benefits, risks, and potential outcomes of each treatment option to help the patient make an informed decision. 
• Treatment Intervention: Once the treatment decision is made, the chosen treatment intervention will be performed. This may involve procedures such as cryotherapy, curettage, electrocautery, laser therapy, or the application of topical agents. The procedure will be conducted according to established protocols and guidelines, ensuring patient comfort and safety. 
• Follow-up and Monitoring: After the treatment intervention, the patient will be provided with appropriate aftercare instructions. This may include wound care, medication application (if applicable), and any necessary follow-up appointments.  
• Long-term Management: Seborrheic keratoses may recur over time, and new lesions can develop. Therefore, long-term management involves regular skin examinations to detect any new or changing lesions. The patient will be advised on self-skin examination techniques and encouraged to report any suspicious or concerning skin changes to their healthcare provider. 

Medication

Future Trends

Media Gallary

References

Seborrheic Keratosis – StatPearls – NCBI Bookshelf (nih.gov) 

Current Understanding of Seborrheic Keratosis: Prevalence, Etiology, Clinical Presentation, Diagnosis, and Management – PubMed (nih.gov) 

Seborrheic Keratosis: What Is It, Causes, Risks & Treatment (clevelandclinic.org) 

Seborrheic keratosis – Symptoms & causes – Mayo Clinic 

Recent advances in managing and understanding seborrheic keratosis – PMC (nih.gov) 

The Prevalence of Seborrheic Keratoses in People Aged 15 to 30 Years: Is the Term Senile Keratosis Redundant? | Dermatology | JAMA Dermatology | JAMA Network