"Tape dermatoscopy": constructing a low-cost dermatoscope using a mobile phone, immersion fluid and transparent...

Medical professionals and indeed the general public have an increasing interest in the acquisition of dermatoscopic images of suspect or ambiguous skin lesions. To this end, good dermatoscopic image quality and low costs are important considerations.

Images of seven lesions (seborrheic keratosis, melanoma in-situ, blue and dermal nevus, basal cell carcinoma and two squamous cell carcinomas) were taken. A novel technique of "tape dermatoscopy" involved: Using immersion fluid (i.e., water, olive oil, disinfectant spray) placed on the flat or slightly elevated lesion;Covering the lesion with transparent adhesive tape with lateral tension;Using ambient indoor or outdoor lighting for illumination (rather than flash photography);Positioning a photographic device at an angle of approximately 45° from the side of the lesion to avoid light reflection;Recording a focused image with a mobile phone or digital camera at a distance of approximately 25-30 cm from the lesion; andEnlarging the image on the screen of the device. Essential dermatoscopic features enabling a correct diagnosis were visible in 6 of the 7 lesions. 'Tape dermatoscopy" images of the lesions were compared to standard dermatoscopy (using a Fotofinder handyscope® in combination with a mobile phone). The latter confirmed the dermatoscopic features in six of seven lesions.

"Tape dermatoscopy" images can be recorded by medical personnel and even the general public without a dermatoscope. However, the limitations of this method are that images may be unfocused, exophytic tumors may be difficult to assess, excess pressure on tumoral blood vessels may lead to compression artefact, dermatoscopic features that are only visible under polarized light are unable to be detected (particularly "crystalline" or "chrysalis" structures) and tumors in certain anatomic locations may be difficult to assess (e.g., edges of nose, ears [demonstrated in one case], nails). Comparative prospective studies are necessary in order to test reproducibility of these preliminary findings, to establish special indications for the technique, and to develop guidelines for its effective use.