Seborrheic keratosis: causes and signs

Seborrheic keratosis: understanding the causes to better recognize it

Seborrheic keratosis is a very common skin condition, especially in people over 50 years old. It appears as benign skin lesions, often confused with other pigmented or warty anomalies. Understanding its causes helps to better grasp this manifestation of skin aging and to avoid unnecessary worry.

While the exact cause of seborrheic keratosis remains unknown, several factors undeniably play a role in its onset. A genetic predisposition appears pronounced, with some members of the same family more frequently developing these growths.

Triggering factors and environmental influences

Besides hereditary factors, age is predominant: seborrheic keratoses mainly appear in middle-aged and older individuals. Furthermore, repeated sun exposure contributes to their development on exposed areas such as the chest, face, or neck.

This form of hyperkeratosis, that is, localized thickening of the stratum corneum of the skin, is accentuated by the years. It thus reflects a natural process, but also potentially accelerated by external factors.

Visible signs: how to identify seborrheic keratosis?

The benign lesions linked to seborrheic keratosis present in various forms but with common easily observable characteristics. Notably, they have a raised appearance, often rough or crusty. These pigmented spots can range from light beige to deep brown, even black, with a texture sometimes comparable to a wart.

The lesions usually measure from a few millimeters to several centimeters and are frequently located on the back, chest, temples, and, in dark skin, on the cheekbones in the form of a black papular dermatosis.

• Shape: oval or round, with an appearance “sitting on the skin.”
• Texture: waxy, scaly, or crusty.
• Color: from beige to black, sometimes with irregular pigmentation areas.
• Evolution: slow, stable over time.

A dermatological diagnosis is essential when the lesion’s appearance is atypical or changes rapidly, in order to rule out any suspicion of melanoma or precancerous lesion.

When should seborrheic keratoses be treated?

In most cases, these lesions do not require any medical intervention if they are not bothersome. However, certain signs justify removal:

• Aesthetic reasons: especially when the lesions are visible, for example on the face.
• Functional discomfort: irritation due to friction or persistent itching.
• Diagnostic doubt: need for a biopsy to confirm the benign nature of the lesion.

Treatment options include cryotherapy with liquid nitrogen, which is frequently used: it causes the lesion to freeze and fall off a few days later. Electrocoagulation, curettage, or the use of dermatological lasers (CO2 or Erbium) are also effective alternatives, particularly for sensitive areas.

In cases of large or suspicious lesions, surgical excision with histological analysis is recommended to ensure optimal follow-up.

Preventing and monitoring seborrheic keratoses in the context of skin aging

While total prevention of seborrheic keratosis remains impossible, it is nevertheless advised to:

• Protect your skin from the sun using SPF 50+ sunscreens, thereby reducing the risk of development on exposed areas.
• Avoid repeated trauma which can irritate existing lesions or promote their appearance.
• Have regular dermatological follow-up in cases of family history or new skin changes.

This vigilance helps distinguish benign lesions from more concerning abnormalities and preserves healthy skin despite the passing years.