Scabies: Advances in Noninvasive Diagnosis

Abstract

Scabies is a common, highly contagious skin parasitosis caused by Sarcoptes scabiei var. hominis. Early identification and prompt treatment of infested subjects is essential, as missed diagnosis may result in outbreaks, considerable morbidity, and significantly increased economic burden. The standard diagnostic technique consists of mites’ identification by microscopic examination of scales obtained by skin scraping. This is a time-consuming and risk-associated procedure that is also not suitable to a busy practice. In recent years, some advanced and noninvasive techniques such as videodermatoscopy, dermatoscopy, reflectance confocal microscopy, and optical coherence tomography have demonstrated improved efficacy in the diagnosis of scabies. Their advantages include rapid, noninvasive mass screening and post-therapeutic follow-up, with no physical risk. A greater knowledge of these techniques among general practitioners and other specialists involved in the intake care of overcrowded populations vulnerable to scabies infestations is now viewed as urgent and important in the management of outbreaks, as well as in consideration of the recent growing inflow of migrants in Europe from North Africa.

A Case Report of Real-Time in vivo Demonstration of Sarcoptes scabiei

“…RCM has also been utilized for infestations such as scabies or pediculosis (4-13). As previously stated, crusted scabies is a relatively challenging entity, for which RCM may prove to be particularly helpful in the diagnosis (2,4,8,9,12). Similar to our report, some authors have provided real-time video recordings of S. scabiei moving within the skin (7,8,10).…”

“…However, the advent of a hand-held device has partially circumvented these problems. More importantly, at present, RCM is only available in some clinics due to the prohibitively high initial cost of setup (2,7,8,11,12).…”

“…Within the scope of dermatology, RCM is most commonly used for diagnosing neoplastic lesions (2). RCM has also been utilized for infestations such as scabies or pediculosis (4-13).…”

“…During its life cycle, the adult female mite excavates a burrow and deposits eggs within the superficial layers of the epidermis (1). Classically, the burrows are localized on the interdigital areas, wrists, nipples, axillae, buttocks, and penile shaft (2). Pruritus, which is the hallmark symptom of scabies, is more intense at night and is believed to be due to an inflammatory reaction against the mite and its feces.…”

“…Epiluminescence microscopy/dermoscopy may also be useful diagnostic adjuncts. Besides light microscopy and dermoscopy, S. scabiei can be visualized using reflectance confocal microscopy (RCM), which is an imaging modality that allows in vivo examination of the skin at a resolution similar to that used during histopathology (2,4,5). As a light source, this technique employs a diode laser and combines the advantage of being non-invasive with the ability to study dynamic events occurring within various layers of the skin.…”