INTRODUCTION
The seborrheic keratosis (SK) is the most common benign skin tumor of middle-aged and elderly adults. It affects roughly 83 million Americans, with an average of 155 new cases of SK diagnosed per month. Forty-three percent of these patients eventually undergo some form of treatment.1-3 SK can occur anywhere on the body, including the nail bed and conjunctiva. These lesions are not only difficult to treat because of their location, but also because they may often recur after removal excision.4-6 Given the wide array of forms these benign skin growths may take, the management of this condition often varies greatly among physicians. As the final component of a three-part series of understanding seborrheic keratosis, this review will discuss the current opinion regarding SK management, with a focus on current treatment options, adverse effects, and therapeutic selection based on identified lesion type, patient preference, and concerns. We will discuss the latest scientific data on new treatments in current clinical investigation. Finally, this review will conclude with a discussion on effective SK treatment strategies aimed at improving clinical outcomes and ensuring patient satisfaction.
When Is Removal Indicated?
Clinicians are commonly faced with the challenge of determining whether to remove an SK and, if so, which modality to utilize. A suggested initial approach is to categorize the lesion as either of medical or cosmetic concern. Several SK subtypes, such as inverted follicular keratosis (IFK) and large cell acanthomas (LCA), can mimic melanoma, pigmented basal cell carcinoma, or squamous cell carcinoma.7 If the lesion in question is easily traumatized, indistinguishable from a malignant lesion, ulcerated, or if it exhibits atypical changes such as increased size or number, inflammatory changes, and/or acute symptoms, the concern for malignancy is high and definitive removal of the lesion is warranted.1 SK can also be a cutaneous red ag of an internal malignancy. For instance, the sign of Leser-Trélat, which describes the sudden appearance or rapid increase in size and number of multiple inflammatory SKs, has been associated with adenocarcinoma, most commonly involving the stomach, ovary, uterus, or breast. Other rare locations that have been reported in literature include carcinomas of the bladder, lung, and larynx.8,9 Dermatosis papulosis nigra (DPN) is another SK subtype that has also been associated with internal malignancies.7 These lesions may often be the only presenting sign in some cases; thus a high degree of clinical suspicion can lead to swifter diagnosis of more ominous internal pathology. However, the sudden eruption of multiple inflammatory SKs should also prompt a thorough review of each patient’s medications. Certain drugs, such as adalimumab, can cause a pseudo-sign of Leser-Trélat, without underlying malignancy.10 In addition, antineoplastic drugs like docetaxel, cytarabine, 5- uorouracil, vincristine, doxorubicin, dactinomycin, cisplatin, and gemcitabine can induce inflammation of existing SKs.7,11 In these cases, resolution of SK occurs following treatment of the underlying condition and cessation of the offending agent.10,11 Therefore, it is also important to consider the temporal relationship between the onset of SK and the start of new medications when deciding whether removal of the lesion is ultimately necessary.
