Lentigo: Causes, Symptoms, and Treatment

Lentigo refers to light brown or dark spots on the skin, often called liver spots. These spots can vary in number and appearance, ranging from harmless to potentially dangerous. While solar lentigo and lentigo simplex are benign, lentigo maligna is precancerous and can progress to melanoma, a type of skin cancer. Recognizing the differences between these types is essential for proper care and treatment.

What is Lentigo?

Lentigines, the plural form of lentigo, describe pigmented spots on the skin that can appear gradually or suddenly. They are often associated with aging or sun exposure but can also have genetic or medical causes.

Types of Lentigo

There are three primary types of lentigo:

1. Lentigo Simplex

   • Commonly seen in childhood or present at birth.
   • Can appear anywhere on the body, regardless of sun exposure.

2. Solar Lentigo

   • Often referred to as age spots or liver spots.
   • Develop due to prolonged sun exposure and are more common with aging.

3. Lentigo Maligna

   • A precancerous condition that may develop into lentigo maligna melanoma (LMM).
   • Characterized by changes such as fuzzy borders, raised surfaces, or discomfort.

Symptoms of Lentigo

Lentigines vary based on their type but often share common traits:

• Clear margins with well-defined edges.
• A flat, oval shape with an even tan to dark brown color.
• Typically painless and stable in size.
• Found in sun-exposed areas (solar lentigo) or across the body (lentigo simplex).

For lentigo maligna, symptoms may progress to include:

• Irregular or fuzzy borders.
• Raised or scar-like textures.
• Itching, bleeding, or discomfort.

What Causes Lentigo?

Lentigo formation depends on its type:

• Solar Lentigo: Caused by ultraviolet (UV) exposure from the sun, tanning beds, or medical UV treatments. UV exposure triggers an overproduction of melanin, leading to dark spots.
• Lentigo Simplex: The exact cause is unclear but may involve genetic predispositions or certain medical conditions.

Risk Factors for Lentigo

Certain factors increase the likelihood of developing lentigo:

• Fair skin.
• Older age.
• Frequent sunburns or UV exposure.
• Radiation therapy.
• Use of psoralen and UV light therapy (PUVA).

Diagnosing Lentigo

A dermatologist plays a key role in diagnosing lentigo. They examine the skin and assess risk factors, family history, and symptoms. Diagnostic tools include:

• Dermoscopy: A handheld device that visualizes skin structures.
• Skin biopsy: Laboratory analysis of skin samples.
• Wood's lamp examination: UV light highlights fluorescence patterns.
• Reflectance confocal microscopy (RCM): Non-invasive imaging for cellular-level examination.

The ABCDE Approach

To evaluate potential skin cancer, dermatologists use the ABCDE rule:

• A - Asymmetry: Uneven shape.
• B - Border: Irregular or blurry edges.
• C - Color: Uneven shades of brown, black, red, or white.
• D - Diameter: Spots larger than 6 mm (pencil eraser size).
• E - Evolution: Changes in size, shape, or elevation.

Treatment Options for Lentigo

While solar lentigo and lentigo simplex are harmless, many people seek treatment for cosmetic reasons or to address precancerous conditions. Common treatments include:

Over-the-Counter (OTC) Creams

Topical products can lighten spots and prevent darkening. Popular ingredients include:

• Alpha hydroxy acids (e.g., glycolic acid): Exfoliate dark skin cells.
• Retinoids (e.g., retinol): Promote skin renewal.
• Vitamin C: Reduces melanin production.
• Kojic acid: Derived from fermented rice wine, it lightens pigmentation.
• Hydroquinone: A bleaching agent.

Prescription Medications

Dermatologists may prescribe stronger formulations containing:

• Hydroquinone or retinoids.
• Azelaic acid: Reduces melanin production.
• Cysteamine: Inhibits melanin synthesis.

Medical Procedures

Several in-office treatments target lentigo by destroying excess melanocytes or promoting new skin growth:

• Laser therapy: Focused light to reduce pigmentation.
• Intense pulsed light (IPL) therapy: Broad-spectrum light treatment.
• Cryotherapy: Freezing spots with liquid nitrogen.
• Chemical peels: Exfoliation with chemical solutions.
• Dermabrasion: Mechanical exfoliation using a textured instrument.

Prevention Tips

Preventing lentigo involves protecting your skin from UV damage:

• Apply sunscreen daily with SPF 30 or higher.
• Avoid tanning beds and limit sun exposure during peak hours (10 a.m.–3 p.m.).
• Wear protective clothing, sunglasses, and wide-brimmed hats.
• Use skincare products with antioxidants to protect against environmental damage.

Related Conditions

Lentigo can resemble or occur alongside other conditions:

• Actinic keratosis: Rough patches caused by sun exposure.
• Seborrheic keratosis: Waxy, raised spots.
• Underlying conditions: Addison's disease or vitamin B12 deficiency.
• Genetic syndromes: Rare conditions like Peutz-Jeghers syndrome or LEOPARD syndrome.

Living With Lentigo

Lentigo spots are generally harmless but can cause cosmetic concerns or health risks in the case of lentigo maligna. Regular dermatological check-ups are vital for early detection and management. Combining preventive measures with treatment options like creams or cosmetic procedures ensures healthier, more radiant skin.

Conclusion

Lentigo, whether benign or precancerous, requires attention to detail in identification and care. Protecting your skin from UV exposure, understanding risk factors, and consulting a dermatologist for concerns are the best strategies to manage this condition effectively.