Overview 

Epidermal nevus syndrome (ENS) is a rare condition that affects multiple body systems. It is mainly recognised by the presence of epidermal nevi, patches of thickened, often raised skin that usually appear in lines or streaks.¹ In addition to these skin changes, people with ENS may also develop problems in the brain and nervous system, eyes, bones, and other organs. ENS is not a single disorder but rather a group of related conditions, such as Schimmelpenning syndrome and nevus sebaceous syndrome, each with its own set of symptoms¹. Because ENS can manifest differently in each person and may impact both appearance and overall health, treatment is often complex. Doctors may need to focus not only on improving the cosmetic appearance of the skin but also on preventing and managing complications in other parts of the body.

This article evaluates the current medical and surgical strategies for managing ENS, exploring their effectiveness, limitations, and evolving therapeutic approaches. 

Pathophysiology of epidermal nevus syndrome 

Epidermal nevi are benign (non-cancerous) growths of skin tissue that form due to changes in certain genes after birth, known as postzygotic somatic mutations.² These genetic changes affect how cells grow and divide. Research has shown that mutations in genes such as FGFR3, HRAS, KRAS, and PIK3CA can cause cells to over-activate their growth pathways, leading to the development of these skin patches.³

This also explains why the lesions often appear in a linear or streaked pattern, following the lines of Blaschko, invisible pathways on the skin that reflect how skin cells developed before birth.⁴

When these mutations occur not just in skin cells but also in other tissues, they lead to more serious health problems. These may include:

• Neurological issues such as epilepsy, developmental delay, or enlargement of one side of the brain (hemimegalencephaly) 
• Skeletal changes like bone deformities 
• Eye problems, including structural abnormalities 
• Heart or vascular defects in some cases

Because ENS can affect multiple organs in various ways, treatment typically requires a multidisciplinary team of specialists, including dermatologists, neurologists, ophthalmologists, orthopaedic surgeons, and others. Both medical treatments and surgical options may be needed, depending on the individual’s symptoms and complications.

Medical treatment options 

Management of epidermal nevus syndrome (ENS) often starts with medical treatments, which can improve the appearance of skin lesions, relieve symptoms, or address complications in other organs. The choice of therapy depends on the severity of the lesions, whether other systems are involved, and the extent to which the condition affects the patient’s quality of life. 

Topical therapies 

Topical therapies are applied directly to the skin and are usually the first line of management for epidermal nevi. They mainly help improve appearance and relieve symptoms like itching or scaling.

• Keratolytics (salicylic acid, urea creams): These soften and remove the thick outer layer of skin, reducing roughness and scaling. The effects are usually temporary⁶
• Topical retinoids (e.g., tretinoin):⁵ These encourage faster skin turnover, which can flatten raised lesions. However, they may irritate, and lesions often come back once treatment stops
• Topical corticosteroids: Helpful when the lesions are inflamed or itchy, but long-term benefit is limited⁵
• Topical sirolimus (mTOR inhibitor): A newer option that can reduce both thickness and discolouration of lesions by targeting the underlying growth pathways involved in ENS⁷

Systemic therapies 

Systemic treatments affect the whole body and are generally reserved for more severe cases or when ENS causes problems beyond the skin.

• Oral retinoids (acitretin, isotretinoin):⁵ These medications can thin out thickened lesions. However, like topical retinoids, the effects often fade once the medication is stopped
• Antiepileptic drugs: For patients with seizures due to ENS, medications such as valproate or levetiracetam are commonly used to control epilepsy⁸
• mTOR inhibitors (oral sirolimus, everolimus): Still under study, these drugs may be helpful in patients with severe multisystem involvement, especially when genetic testing shows abnormalities in the P13K/AKT/mTOR pathway⁷

Laser therapy 

Laser treatment is often considered a bridge between medical and surgical options, particularly for improving cosmetic appearance.⁵

• Carbon dioxide (CO₂) laser: Destroys the lesion by vapourising the tissue. It often gives good cosmetic results, but lesions may return over time⁶
• Erbium: YAG laser: Works similarly to CO₂ lasers but allows more precise removal with less risk of scarring⁶
• Pulsed dye laser (PDL): Best suited for lesions that have a vascular (blood vessel) component. It is less effective for thick, rough lesions⁹

Surgical treatment options 

Surgery is often the most effective treatment for large, disfiguring, or symptomatic epidermal nevi. It is especially important when there is a risk that a lesion might turn cancerous.

Excision 

• What it is: Complete surgical removal of the affected skin (full-thickness excision)⁵
• Benefits: Provides the most permanent solution and is considered the gold standard for localised lesions
• Limitations: Scarring is common, and depending on the size and location, removal may also affect movement or function
• When used: Particularly recommended if the lesion shows suspicious changes such as rapid growth, ulceration, or unusual pigmentation, which could suggest malignancy

Dermabrasion and cryosurgery

These are less invasive alternatives but generally less effective than excision. 

• Dermabrasion: Uses a rotating instrument to sand down the top layers of skin. It can improve appearance but often does not remove the lesion completely, so regrowth is common⁵
• Cryosurgery: Freezes the lesion with liquid nitrogen. Results vary; some patients achieve good cosmetic outcomes, but risks include scarring and areas of lighter skin (hypopigmentation)⁵

Skin grafting and reconstruction 

When large lesions are removed, simple closure of the wound may not be possible. In these cases:

• Skin grafts (often split-thickness grafts) are used to cover the excised area¹⁰
• Tissue expanders may be placed under nearby healthy skin to stretch it, providing extra skin for reconstruction¹¹
• Flap reconstruction can also be used to restore both function and appearance after extensive excision¹²

Multidisciplinary management of systemic involvement 

Since ENS affects multiple organ systems, management extends beyond dermatological treatment. 

• Neurological care: Seizures are common in ENS and are usually managed with antiepileptic medications. In some rare cases of severe, uncontrollable epilepsy, surgical options such as hemispherectomy (removing or disconnecting one side of the brain) may be considered
• Ophthalmological care: Eye problems like coloboma (missing tissue in the eye), cataracts, or strabismus (crossed eyes) may require corrective surgeries to preserve or improve vision
• Orthopaedic care: Bone abnormalities, including scoliosis (curvature of the spine) or differences in limb strength, may need surgical correction to restore function and mobility
• Cardiovascular care: Some patients develop congenital heart defects, which require careful monitoring and, if necessary, medical or surgical interventions

Emerging and future therapies 

Recent advances in understanding the genetic causes of ENS are opening new possibilities for more precise and effective treatments. 

Targeted molecular therapies

Advances in understanding the genetic basis of ENS suggest a future role for targeted inhibitors (e.g., FGFR inhibitors, MEK inhibitors).¹³ Early preclinical studies are ongoing. 

Gene therapy and CRISPR 

Somatic mosaicism poses a challenge, but gene-editing strategies targeting postzygotic mutations are under exploration in other genetic skin disorders and may eventually apply to ENS.¹⁴

Combination approaches 

The combination of surgical excision with adjuvant laser resurfacing or topical sirolimus may improve cosmetic outcomes and reduce recurrence. 

FAQs

Can epidermal nevus syndrome be cured?

No, ENS cannot be cured as it results from postzygotic mutations. Treatment focuses on symptom control, cosmetic improvement, and management of systemic complications. 

Do epidermal nevi recur after treatment?

Yes, recurrence is common after medical or laser therapy. Complete surgical excision offers the lowest recurrence rate but may result in scarring.

Are epidermal nevi cancerous?

Most epidermal nevi are benign, but rare cases of secondary malignancy (e.g. basal cell carcinoma, squamous cell carcinoma) have been reported, necessitating monitoring.

Summary 

Epidermal nevus syndrome (ENS) is a rare, multisystem condition requiring individualised treatment strategies. Medical therapies such as topical keratolytics, retinoids, and mTOR inhibitors provide symptomatic relief and cosmetic improvement, while systemic treatments target neurological and other extracutaneous manifestations. Surgical approaches, particularly excision, remain the most definitive option for localised lesions, though scarring and recurrence pose challenges. Laser therapies serve as minimally invasive alternatives with promising cosmetic outcomes. Multidisciplinary care is essential due to systemic involvement, and emerging molecular therapies may soon provide more targeted, durable treatments.