Staining of the furrows in the palm of the hand. The eccrine pores and the furrows can be clearly observed.
Melanoma in situ on the sole of the foot, 12 mm in diameter. The furrow ink test around the lesion is useful for dermoscopic analysis.
Uhara H, Koga H, Takata M, Saida T. The Whiteboard Marker as a Useful Tool for the Dermoscopic “Furrow Ink Test”. Arch Dermatol. 2009;145(11):1331–1332. doi:10.1001/archdermatol.2009.275
Determination of whether pigmentation is predominant in furrows or ridges is very important for accurate diagnosis of pigmented lesions in the volar skin.1- 3 Recently, Braun et al4 reported the benefits of dermoscopy with staining by liquid ink, which they called the “furrow ink test.” This method is very useful when differentiation between furrow and ridge is difficult under a polarizing lens. However, staining with liquid ink from a fountain pen sometimes shows a fuzzy image because the ink can be easily removed from the furrows by wiping. Therefore, we have recently begun to use whiteboard marker pens containing alcohol-based ink.
The method is easy: moisturize the skin surface with a wet towel, mark the outside of the lesion with the pen, and then wipe the skin surface with a dry paper towel. We can see the sharply staining furrows not only under the polarizing lens but also with ultrasound jelly or water-soluble surgical lubricant (Figure 1). After observation, the ink in the furrows can be removed easily with water.
In general, the ink used in whiteboard markers writes evenly and consistently and erases easily. It is composed of colorants, alcohol, and binder resin. The binder resin is insoluble in alcohol. Once the composition is transferred to a white board, the alcohol evaporates, leaving the binder resin and colorant as a friable film separated from the board that can therefore be removed easily from the smooth surface. However, the ink will adhere to any scratches on the surface. Consequently, it cannot simply be removed with a dry cloth but is washable in water. This characteristic is appropriate for our purpose, which is staining only the furrows of the skin.
Furthermore, using this type of pen, we can draw in a restricted area. Staining only the normal skin around the lesion can allow us to visualize the patterns of the normal furrows, which will facilitate understanding of the dermoscopic patterns of the pigmented lesion (Figure 2). The whiteboard marker can be obtained easily and is a useful tool for the dermoscopic furrow ink test.
Correspondence: Dr Uhara, Department of Dermatology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan (firstname.lastname@example.org).
Accepted for Publication: June 2, 2009.
Author Affiliations: Department of Dermatology, Shinshu University School of Medicine, Matsumoto, Japan.
Author Contributions: Dr Uhara had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Uhara. Acquisition of data: Uhara, Koga, Takata, and Saida. Analysis and interpretation of data: Uhara, Koga, and Saida. Drafting of the manuscript: Uhara, Koga, and Takata. Critical revision of the manuscript for important intellectual content: Uhara and Saida. Administrative, technical, and material support: Uhara. Study supervision: Uhara and Saida.
Financial Disclosure: None reported.