A case of seborrheic keratosis lesions localized to eyebrow tattoos

Dear Editors, Seborrheic keratoses (SKs) are benign epidermal neoplasms predominantly encountered in middle-aged and elderly individuals and are characterized by cutaneous lesions composed of papules and plaques with clear borders. In clinical dermatological practice, SK can occur on all hair-bearing areas of the body, but the most common sites of the lesions are the face and upper trunk.1 Herein, we report a case of multiple SKs on both eyebrows secondary to eyebrow tattoos in a 30-year-old immunocompetent Chinese woman with a 3-year history. Physical examination revealed multiple clusters of keratotic papules and plaques on her bilateral eyebrows (Figure 1). Dermatoscopy revealed a cerebriform sulcus and gyrus pattern with fissures and ridges (Figure 2a). The main clinical differential diagnosis was verrucae planae. The clinical features of the lesions and the characteristic dermatoscopic features were in favor of the diagnosis of SKs. The option of a tissue biopsy was discussed and finally performed at the patient's request. Histopathologic examination found typical characteristics of SKs but no definitive features of verruca plana (Figure 2b). In addition, the sample was tested for the presence of human papillomavirus (HPV) using the HPV genotyping kit for 23 types (Yaneng BIOscience [Shenzhen] Co., Ltd.). HPV polymerase chain reaction (PCR) showed a negative result for HPV serotypes 6, 11, 16, 18, 31, 33, 35, 39, 42, 43, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, 81, 82 and 83. Given the persistent suspicion of verrucae, additional HPV testing was performed by nested PCR (Sangon Biotech (Shanghai) Co., Ltd.), but this did not yield any HPV PCR products. Therefore, the lesions were finally considered to be SKs. To our knowledge, only four other cases of lesions with features of SKs localized to tattoos have been characterized as HPV-negative.2-5 However, the relative paucity of reports of similar SKs lesions localized to eyebrow tattoo markings underscores the novelty of this case. Most similar cases have involved verrucae vulgares related to tattoos.6, 7 Furthermore, as shown in our case, the SKs were mainly located on brown eyebrow tattoos. Although the exact pathophysiological mechanism leading to the lesions is unclear, we could consider a reactive process in response to epidermal injury, called the Koebner phenomenon, which could be caused by an eyebrow tattoo needle. However, there was no histological evidence that an underlying dermal stimulus could induce hyperplastic responses.2 In addition, ultraviolet-induced dermal injury has been reported to induce reactive SKs.8 In conclusion, the occurrence of SK associated with tattoos is rare and unpredictable. Our case is interesting because it supports the notion that trauma may be a predisposing factor for SK. In addition, two other cases of eruptive lesions with Koebner's phenomenon localized to tattoos have been described.9 Therefore, a word of caution to clients and tattooists is that there is a risk of a new onset of SKs in the tattooed area. Finally, we present this case to further the understanding of tattoo-associated dermatoses and the clinical differential diagnosis of lesions. We thank Xu-Peng Tang, Department of Pathology, First Hospital of Shanxi Medical University for his contribution to the selection of the histopathology images. None.