Using ultraviolet dermoscopy in diagnosing scabies

Abstract

The latest generation ultraviolet (UV) dermatoscopes, which emit UV light at a wavelength of 365 nm and enlarge lesions, are practical devices that can facilitate the diagnosis and follow-up of some dermatological diseases with fluorescence that can be observed in skin lesions. In 305 patients, 468 tunnels were evaluated: first in polarized mode and later in UV mode. The recorded samples were compared one-to-one by the same dermatologist. Due to the study's design, images were examined in three stages: tunnel borders, tunnel content and mite appearance. In UV mode, the entire body of mites gives a bright reflex along with an oval-shaped diagnostic clue well beyond the delta sign. The borders of the tunnel reflect brightly in UV mode, with borders that are more sharply visible than in polarized mode. Although the tunnel content cannot be clearly distinguished in polarized mode, especially in people with hyperkeratotic palms, or 'working hands' (e.g. farmers, mechanics and construction workers), with the bright reflex, the tunnel borders in UV mode give a bright reflection and provide a clear view of tunnels. Tunnel content gives a bright reflection in UV mode. Our results show that UV dermatoscopes provide more effective and clearer images than polarized dermatoscopes in the diagnosis of scabies.