A case of Bowen’s disease possibly attributed to chronic stimulation by a metal wristwatch

owen’s disease, Squamous Cell Carcinoma (SCC) in situ, is a ommon skin cancer in elderly people, and its causal factors nclude sun exposure, irradiation, arsenic exposure, burn, car, injury, Human Papillomavirus (HPV), and immunosupressive status. However, Bowen’s disease occurring on hronically stimulated sites has rarely been reported.1 We eport herein a case of Bowen’s disease on the wrist possibly aused by chronic stimulation by contact with the patient’s etal wristwatch. F t m

Clinical features showing well-defined erythematous plaque with erosion and crusts in the area covered by the metal wristwatch on the left wrist.
Bowen's disease occurred at the site of a scar from an injury caused by a tin can as long as 50 years previously. 1 It was reported that cutaneous scars subsequent to burns, radiation, trauma, and vaccination, are vulnerable sites for the development of neoplasms. 4 Chronic stimulation or dental metal allergy have been reported as causes of oral SCC. In a report by Weber et al., among the 65 patients with oral SCC, 34% showed an allergic reaction to at least one metal that was immediately adjacent to the cancer site. The rate was 1.57 times higher than that of the controls. 5 In the present case, we speculate that superficial damage may have been induced by chronic stimulation/friction with a metal wristwatch, leading to the development of Bowen's disease during the repetitive repair process. The current case suggests that even chronic minor stimulation or friction without penetrating trauma or dermal injury may cause Bowen's disease if repeated for a long time. Further studies are needed to clarify the causative mechanisms of Bowen's disease.

Financial support
None declared.

Authors' contributions
Maki Takada wrote the initial draft of the manuscript. Toshiyuki Yamamoto assisted in the preparation of the manuscript. Masato Ishikawa and Yuka Hanami performed data collection, analysis, and interpretation. All authors have read and approved the final version of the manuscript.

Conflicts of interest
None declared.

Dear Editor,
Reed nevi (RNs) are almost exclusively junctional neoplasms distinguished as a variant of Spitz nevus (SN) by their significant melanogenesis and growth pattern. Acral presentation of SN is rare and has specific clinical and histopathological features. 1 Nonetheless, dermoscopic findings of SN and its variants on the acral skin are poorly documented. 2 Herein we describe a case of RN on the volar skin of a finger in which parallel ridge pattern was observed by dermoscopic examination.
ଝ Study conducted at the Department of Dermatology, Arnau de Vilanova University Hospital, Lleida, Spain.
A 9-year-old boy presented with an asymptomatic pigmented lesion on his right hand. He had detected the lesion 8 months previously and had enlarged gradually. He had no personal or family history of malignant tumors. Physical examination revealed an asymmetrical dark brown macule, 13×3 mm in size, located on the volar region of the second right finger. The lesion exhibited an atypical linear morphology similar to a crescent moon (Fig. 1A). Dermoscopic findings showed a brownish parallel ridge pattern with some streaks at the periphery (Fig. 1B). A complete surgical excision was done to rule out malignancy. Histological examination revealed several small nests, vertically oriented, composed of heavily pigmented spindled melanocytes along the dermo-epidermal junction (Fig. 1C---D). No melanocytes were seen in the dermis. A diagnosis by an RN was done.
Acral SNs understood by those located on soles, palms and fingers are infrequent, being reported to comprise less than 2% of all SNs. 1 They are more common in young female adults, more frequently located on the feet, and larger than acral melanocytic nevi. 1 Acral RN or ''pigmented spindle-