Managing Seborrheic Keratosis: Evolving Strategies and Optimal Therapeutic Outcomes
September 2018 | Volume 17 | Issue 9 | Original Article | 933 | Copyright © September 2018
Stephanie Kao BA,a Alexi Kiss MD,b Tatiana Efimova PhD,b,c Adam J. Friedman MDc,d
aThe George Washington University School of Medicine & Health Sciences, Washington, DC bDepartment of Anatomy and Cell Biology, The George Washington University School of Medicine & Health Sciences, Washington, DC cDepartment of Dermatology, The George Washington University School of Medicine & Health Sciences, Washington, DC dDepartment of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY
Seborrheic keratosis (SK) is the most common skin tumor seen by dermatologists in everyday practice. Although the lesions are mostly benign, many patients still elect to have asymptomatic SK removed. The historical standards of treatment are cryosurgery and electrocautery, two surgical options that are effective at lesion removal but have high rates of postoperative adverse events such as treatment-site scarring and pigmentary alterations. The cosmetic outcomes of SK treatment modalities are of keen interest to dermatologists, as the American population becomes increasingly more diverse. In this article, the inclusion of darker Fitzpatrick skin types into clinical studies investigating post-treatment side effects of SK therapy is reviewed. The recent approval of a 40% hydrogen peroxide topical formulation is discussed in light of these issues, and several non-invasive topical treatments that optimize cosmetic outcomes of SK lesion removal are highlighted. Finally, treatment strategies aimed at reducing cost and minimizing the burden of adverse sequelae are provided.
J Drugs Dermatol. 2018;17(9):933-940.
Seborrheic keratosis (SK) is one of the most common dermatologic lesions and is therefore the most common skin tumor seen by dermatologists in everyday practice 1. They are mostly benign, and are most frequently removed for cosmetic reasons.2 SK lesions can occur anywhere on the body, but are most commonly located on the face, neck, and trunk while sparing the palms and soles. They present as round or oval, sharply demar- cated papules and plaques that appear “stuck” on the surface of skin. SK surface texture is highly variable exhibiting a range of appearances from rough and keratotic to smooth and waxy and even flat and macular, the latter presentation occurring especially in SKs that appear initially as a lentigo.3 Despite the frequency with which patients pursue dermatology visits for evaluation and often cosmetic removal, both the literature on this condition and armament of effective treatment options are surprisingly limited.4 Although the majority of SKs are benign, many patients elect to have them removed due to a possibility of malignancy, itching, irritation, and/or cosmetic reasons. The number of SKs generally increases with age, and the lesions have colloquially come to be termed “age spots”. As such, dermatologists frequently hear from patients that they desire removal of SK lesions in order to main- tain a more youthful appearance and improve their quality of life.4 An observational study conducted across 10 dermatology practic- es by Del Rosso et al highlighted how SKs affect quality of life and treatment concerns. 61% of patients, primarily women, reported covering their SKs with makeup, specific hairstyles, or clothing.5 Furthermore, the data revealed that patients most frequently elected to have asymptomatic SKs removed due to concerns that they may be something serious (57%), not liking their appearance (53%), or not liking how they feel when touched (44%).5 Common reasons that spur patients to decline treatment are the risks of scarring or pigment changes.6 Darker skinned patients, in particu- lar, are more prone to post-inflammatory hypo or hyperpigmenta- tion after SK treatment. Post-inflammatory hyperpigmentation occurs when post-inflammatory cytokine secretion causes increased melanin production. Consequently, melanin is abnormally trans- ported into the dermis where it is trapped by macrophages in the papillary dermis leading to superficial hyperpigmentation.7 The pathophysiology of post-inflammatory hypopigmentation is more nebulous and has been proposed to be controlled by autosomal dominant genetic endogenous pigmentary factors that follow “in- dividual chromatic tendency”.8 The “individual chromatic tendency” posits that people with weak melanocytes, which are highly susceptible to damage, are more likely to develop hypopigmentation, and that dark-skinned people with weak melanocytes are prone to develop hypopigmentation.8,9 These factors may explain why certain individuals develop hyperpigmentation and others hypopigmentation. Repigmentation may occur but is not predictable.
Currently, cryosurgery and electrocautery are the two most commonly employed techniques to physically resolve an SK.10,11 Cryosurgery destroys SK lesions by inducing ice crys-