Seborrheic keratoses are very common benign lesions of the epidermis, exhibiting a wide variety of clinical appearances and arising from the proliferation of epidermal cells. Specifically, there is an increase in the thickness of the stratum corneum, the outermost layer of the skin. They usually appear in individuals over the age of 30. The majority of people develop at least one lesion during their lifetime, with an incidence of about 35% in the general population.
They cause primarily cosmetic concerns and, in some cases, due to their location, they may become irritated and inflamed.
Dermatology has not yet determined the exact pathogenic mechanism leading to the development of seborrheic keratoses. They are generally considered part of the natural aging process, with some hereditary predisposition recognized, but no racial predilection. Chronic exposure to ultraviolet radiation is also an important factor in their appearance.
Seborrheic keratoses usually do not cause symptoms but can sometimes cause discomfort. The lesions may occasionally itch. In other cases, due to their location, irritation or injury can occur because they rub against or get caught on clothing.
Clinically, seborrheic keratoses show great variability and different degrees of pigmentation. They appear as solitary or multiple well-demarcated lesions, with colors ranging from white, pink, black, or a combination of colors. Their surface may be smooth, scaly, or verrucous, and they can be found anywhere on the body except the palms and soles. Their shape varies from oval, round, to irregular. The term dermatosis papulosa nigra refers to seborrheic keratoses occurring in individuals of African descent, while stucco keratosis describes seborrheic keratoses commonly found on the shins of elderly Caucasian individuals.
They are generally benign lesions. Differential diagnosis, depending on the type of seborrheic keratoses, should be made from melanocytic nevi, pigmented actinic keratoses, melanoma, pigmented basal cell carcinoma, and others.
With dermoscopic examination, we exclude the possibility of a melanocytic lesion.
We identify specific features of seborrheic keratoses, which include:
- Comedo-like openings
- Fissures (cerebriform or verrucous appearance)
- Milia-like cysts
- Fingerprint-like pattern
- Forked (branched) vessels
Treatment of seborrheic keratoses is performed solely for cosmetic and practical reasons, unless there is doubt about their diagnosis during clinical examination and dermoscopic analysis.
The recommended treatment options include:
1. Curettage
2. Cryosurgery
3. CO2 LASER application (the most popular and commonly used method)
4. Surgical excision, suturing, and histological examination when there is diagnostic uncertainty.
If you have previously been diagnosed by a dermatologist with seborrheic keratosis, it is advisable to visit them if you notice changes in the lesion’s color, size, or shape. Also, if it develops symptoms such as intense itching, swelling, ulceration, or bleeding. Finally, if you observe an increase in the number of lesions.
Complete removal of a seborrheic keratosis by an experienced dermatologist is usually accompanied by a very low chance of lesion recurrence. However, individuals predisposed to developing seborrheic keratoses may develop new, unrelated lesions over time.