Dermoscopy of Burrow Ink Test in a Case of Scabies (Dermoscopic Burrow Ink Test: D-Bit)

Abstract

A 14-year-old girl residing in a boarding school complained of itching over the web spaces of both hands, wrists, trunk, and ankle area for 3 weeks, which was more intense during bedtime. Many of her colleagues at the boarding school had similar complaints.

Cutaneous examination showed multiple papular eruptions and excoriation in the web spaces of both hands, wrist joint, peri-umbilical area, and ankles. A dermoscopy examination of one of the papular lesions showed a greyish-white curvilinear tract (Figure 1a). Burrow ink test (BIT) was performed by gently rubbing fountain pen ink over the papular lesion and excess ink was wiped off using an alcohol swab after 1 min, which on dermoscopy showed an ink-filled blue curvilinear tract with few filling defects (Figure 1b).

The burrow ink test is a simple, non-invasive test that can rapidly screen suspected cases [1, 2]. Performing dermoscopy after a burrow ink test over multiple lesions can increase the chance of a positive test. Literature suggests that the best place to find a burrow lesion is the medial aspect of the hypothenar area of the hands and wrists [3].

To conclude, a dermoscopy of the burrow ink test can better visualize the chances of locating a burrow.