Drop dermoscopy for teledermatology

Technology challenge

There has been an explosion in the practice of teledermatology recently because of the COVID-19 pandemic. This includes patient-initiated consultations. One of the main limitations of patient-initiated consultations is the difficulty of incorporating dermoscopy.

Solution

A drop of clear alcohol-based sanitizer is applied over the lesion to be examined, and the patient (or a helper) takes a photograph of the lesion through the fluid. The fluid reduces the reflection from the surface and helps visualization of the subsurface structures (Figs 1 and 2 ). Any smartphone or point-and-shoot camera is good enough for the imaging, making it easy to transfer the image to the dermatologist. The quality and resolution are better when dedicated cameras with macro mode capabilities are used.

Fig 1.

A, Melanocytic nevus: clinical image. B, Image taken after applying alcohol solution.

Fig 2.

A, Small cherry angioma: clinical image. B, Image taken after applying alcohol solution.

Blum and Giacomel¹ have previously described a concept called tape dermoscopy, in which smartphones are used to take dermoscopic images of skin lesions after the immersion fluid is applied, followed by covering of the area with a transparent adhesive tape. The method we describe is simpler and faster, and it avoids the practical difficulties of having to apply adhesive tape over a liquid surface. The main limitations in our method are the minimal magnification (although the inherent zoom of the capture device can be used) and the reflection of the flash interfering with the image quality. The reflection can be reduced by trying out different angles while taking the image. Although the quality of the dermoscopy is obviously not comparable to that of standard dermoscopes, this can be an easy-to-use, simple screening and triage tool in the context of patient-initiated teledermatology.