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

Scabies is a pruritic dermatosis caused by the ectoparasite Sarcoptes scabiei var. hominis. The diagnosis of scabies is usually made on clinical grounds, but histopathological and/or dermoscopic examinations may sometimes be of assistance. However, these diagnostic modalities do not offer a detailed in vivo demonstration of the motile microorganism. Reflectance confocal microscopy (RCM) is a relatively novel imaging modality that permits in vivo examination of the skin at a resolution similar to that used during similar to histopathologic resolution. Here, a patient with crusted scabies is presented in whom a brief section of the lifecycle of S. scabiei was captured by RCM. Using this advanced imaging modality, the ectoparasite's motion within the human host can be examined for clinical or research purposes and the mite's viability may be assessed to monitor the response to treatment.

In vitro acaricidal activity of 1,8-cineole against Sarcoptes scabiei var. cuniculi and regulating effects on enzyme activity.

1,8-Cineole found in many essential oils is a monoterpene and acts as a repellent against Sarcoptes scabiei var. cuniculi. In the present study, the acaricidal activity of 1,8-cineole against S. scabiei var. cuniculi was evaluated and the acaricidal mechanism was also investigated by assaying enzyme activities. The results showed that the lethal concentration of 50% (LC50) value (95% confidence limit (CL)) and the lethal time of 50% (LT50) value (95% CL) of 1,8-cineole were 2.77 mg/mL and 3.606 h, respectively. The pathological changes under transmission electron microscopy showed that the morphology of the mitochondria was abnormal, the cell nuclear membrane was damaged, and the nuclear chromatin was dissoluted. The activities of superoxide dismutase (SOD), glutathione-s-transferases (GSTs), monoamine oxidase (MAO), nitric oxide synthase (NOS), and acetylcholinesterase (AChE) were significantly changed after treatment with 1,8-cineole for 4, 8, 12, and 24 h. SOD and GSTs are associated with the protection mechanism of scabies mites. And, the activities of SOD and GSTs were increased as compared with the control group. MAO, AChE, and NOS are associated with the nervous system of scabies mites. The activity of MAO was increased whereas the AChE was suppressed. The activity of NOS was suppressed in the high-dose group whereas increased in the middle-dose group and low-dose group. These results indicated that the mechanism of 1,8-cineole mainly attributed to the changes of these enzyme activities related to the nervous system of scabies mites.

Genetic epidemiology and pathology of raccoon-derived Sarcoptes mites from urban areas of Germany.

The raccoon, Procyon lotor (Carnivora: Procyonidae), is an invasive species that is spreading throughout Europe, in which Germany represents its core area. Here, raccoons mostly live in rural regions, but some urban populations are already established, such as in the city of Kassel, or are starting to build up, such as in Berlin. The objective of this study was to investigate Sarcoptes (Sarcoptiformes: Sarcoptidae) infections in racoons in these two urban areas and to identify the putative origin of the parasite. Parasite morphology, and gross and histopathological examinations of diseased skin tissue were consistent with Sarcoptes scabiei infection. Using nine microsatellite markers, we genotyped individual mites from five raccoons and compared them with Sarcoptes mites derived from fox, wild boar and Northern chamois, originating from Italy and Switzerland. The raccoon-derived mites clustered together with the fox samples and were clearly differentiated from those of the wild boar and chamois samples, which suggests a fox origin for the raccoon mange infection. These results are evidence of the cross-transmission of S. scabiei among wild carnivores. Although our results cannot elucidate whether raccoons became infected by frequent interaction with endemically or epidemically infected foxes or whether these cases resulted from occasional contacts among these animal species, they do nevertheless show that pathogens can be shared among urban populations of native and invasive carnivores.

Studies on the acaricidal mechanism of the active components from neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi.

Octadecanoic acid-3,4-tetrahydrofuran diester, isolated from neem (Azadirachta indica) oil, exhibited potent acaricidal activity against Sarcoptes scabiei var. cuniculi. In this paper, the acaricidal mechanism of octadecanoic acid-3,4-tetrahydrofuran diester against Sarcoptes scabiei var. cuniculi was evaluated based on pathologic histology and enzyme activities. The results showed that after compound treatment for 24h at a concentration of 20mg/mL, the lesions of mites were prominent under transmission electron microscopy. The lesions consisted of the lysis of dermis cell membranes and cell nuclear membranes, mitochondrial morphological abnormalities, the drop of spinal disorders, and mitochondrial vacuolization. The activity of superoxide dismutase (SOD), peroxidase (POD), glutathione-s-transferases (GSTs), and Ca(2+)-ATPase of mites significantly changed after treatment with octadecanoic acid-3,4-tetrahydrofuran diester compared with the control group. The activities of SOD, POD, and Ca(2+)-ATPase were significantly suppressed, whereas that of GSTs was activated. These results indicated that the mechanism of the acaricidal activity of octadecanoic acid-3,4-tetrahydrofuran diester was mainly achieved through interference with the energy metabolism of mites, thus resulting in insect death.

Detection of living Sarcoptes scabiei larvae by reflectance mode confocal microscopy in the skin of a patient with crusted scabies.

Scabies is an intensely pruritic disorder induced by a delayed type hypersensitivity reaction to infestation of the skin by the mite Sarcoptes scabiei. The diagnosis of scabies is established clinically and confirmed by identifying mites or eggs by microscopic examination of scrapings from the skin or by surface microscopy using a dermatoscope. Reflectance-mode confocal microscopy is a novel technique used for noninvasive imaging of skin structures and lesions at a resolution compatible to that of conventional histology. Recently, the technique was employed for the confirmation of the clinical diagnosis of scabies.We demonstrate the first ever documentation of a larva moving freely inside the skin of a patient infected with scabies.

Accuracy of standard dermoscopy for diagnosing scabies.

BACKGROUND: Scabies is a contagious skin infestation caused by the human mite Sarcoptes scabiei. The usual reference method for definitive diagnosis is ex vivo identification of the mite with microscopic examination of skin scrapings. We compared diagnostic accuracy of in vivo dermoscopic (DS) mite identification using a pocket handheld low-magnification DS with the reference method. METHODS: We conducted a prospective, nonrandomized, evaluator-blinded, noninferiority study to compare sensitivities (main outcome) and other diagnostic properties of DS and microscopic examination of skin scrapings. Among 756 patients with a presumptive diagnosis of scabies consulting in one center, 238 were sequentially submitted to the two diagnostic procedures. Three dermoscopists (one expert, two inexperienced) were involved. Diagnostic strategies using clinical skills only, DS results, and a combination of both were compared. RESULTS: Sensitivities were 91% (95% confidence interval: 86-96) for DS and 90% (95% confidence interval: 85-96) for microscopic examination of skin scrapings (P = .005 for noninferiority). Specificities were 86% (95% confidence interval: 80-92) for DS and 100% (by definition) for microscopic examination of skin scrapings. DS sensitivities were similar for the expert and inexperienced dermoscopists, whereas differences were observed in specificities. However, diagnostic accuracy of inexperienced dermoscopists steadily increased during the study. Compared with clinical-based, DS-based treatment decision rule minimized the number of false-positive and false-negative findings, whereas a treatment decision rule based on combination of clinical presumption and DS result drastically reduced the number of patients with scabies left untreated. LIMITATIONS: There is no definitive standard for ruling out the diagnosis of scabies. CONCLUSIONS: Standard DS with a handheld DS is a useful tool for diagnosing scabies, with high sensitivity, even in inexperienced hands. It greatly enhances clinical skills for making treatment decisions.

Case report: teledermatology and epiluminescence microscopy for the diagnosis of scabies.

We wish to share images from a patient seen in our teledermatology program. Due to the absence of on-site dermatology services at the Togus, Maine, Department of Veterans Affairs, and associated community clinics for veterans in Aroostook, Bangor, Calais, and Rumford, we created a program to provide dermatologic expertise from Providence, Rhode Island. Patients referred for this service were evaluated by a nurse practitioner, who obtained a history, performed a physical examination, and captured digital images of the affected area of skin, including epiluminescence microscopic images where indicated. These data were then retrieved at the Providence (host) site and reviewed by a dermatologist, who formulated an impression and plan that was then implemented by the remote site in Maine. This approach, which involves image capture at the remote site and later review of images at the host site, is the "store-and-forward" method, which appears to be a relatively cost-effective means of providing this service from a distance.

The behaviour of Sarcoptes scabiei var. hominis in human skin: an ultrastructural study.

The biology of Sarcoptes scabiei var. hominis is poorly understood because of the lack of an in vivo or in vitro propagation system. To obtain more information on the mite behaviour in its natural habitat we conducted an ultrastructural study of burrows in a number of patients with common scabies. Scanning electron microscopy furnished attractive images of the tunnel, parasite body and eggs architecture and demonstrated the presence of holes in the tunnel roof probably representing aeration structures. Transmission electron microscopy showed a marked keratinocyte damage around burrowing mites, well evident ahead of the mite capitulum also. Faecal pellets containing keratinocyte micro-organelles (melanosomes and mitochondria) were documented in posterior midgut. For the first time we disclosed the adhesion mechanism of eggs to the burrow floor. We showed that the typical finger-like projections of the outer layer of the egg shell gradually disappear where the eggs are in contact with the tunnel floor. This allows the inner layer of the egg shell to fuse and stick with the damaged keratinocytes lining the tunnel floor. Our observation substantiates that Sarcoptes scabiei produces a proteolytic substance (salivary secretions?) that has a key role in its life cycle allowing burrowing, feeding and eggs-burrow adhesion.

Análisis de las poblaciones de sarcoptes scabiei (acaridida: sarcoptidae) en un paciente con escabiosis noruega de Costa Rica / Analysis of the sarcoptes scabiei (acaridida: sarcoptidae) populations in a case of norwegian scabies at Costa Rica

Se realizó un análisis de las poblaciones de ácaros sarcoptes scabiei (acaridida: sarcoptidae) presentes en un paciente con escabiosis noruega que presentaba lesiones en espalda -glúteos, muslo derecho, axila izquierda. mano derecha y codo izquierdo. Se encontraron formas evolutivas del ácaro en todos los sitios con lesiones, siendo la espalda-glúteos el lugar de mayor densidad de ácaros (p< 0,01)

[Clinical and scanning electron microscopic studies on Norwegian scabies infection].

Two typical cases of Norwegian scabies were studied clinically, scanning electron microscopically and histopathologically. Case 1 was a boy with Down's syndrome and case 2 was a man with adult T cell leukemia/lymphoma. Their clinical pictures showed hyperkeratotic plaques and warty crusts on hands, feet, ears, elbows and buttocks. Direct examination of the KOH preparation revealed many embryonated sarcoptic eggs, postpartum egg-shells, fecal pellets, larvae and male and female adult mites. Histopathologic examination showed several burrows inside the thick horny layer. Many sarcoptic egg-shells, mites and fecal pellets were found in the burrows. Psoriasiform hyperplasia and parakeratosis were noted, too. The size and shape of the sarcoptic eggs and the detailed structure of mites and molt were observed by using a scanning electron microscope. Besides, hook-like structures were noted at the tarsi of both forelegs and hindlegs. We suggest that the larvae crawl out from longitudinal openings in the egg-shell by the use of hook-like structures. The mites also used these hook-like structures to make the burrows. Scanning electron microscopy provides a good method to understand the dynamics of these burrowing parasites. It is helpful in illustrating the behavior of the scabies mites in their burrows in Norwegian scabies patients.

Scanning electron microscopy of sarcoptic mange lesions in swine.

Scanning electron microscopy revealed that lesions of sarcoptic mange in swine, pass through 3 different stages. During the first 3 weeks of infestation, adult female mites tunnel into the epidermis. During the following 3 or 4 weeks, the surface openings of these tunnels become covered with keratinized epidermal crust which increases in thickness. After 7 weeks of infestation, the crust falls off, the tunnel openings become apparent again and most of the mites vacate these tunnels.

Vesicular scabies in an adult.

We describe an unusual vesicular eruption occurring secondary to scabies in an elderly patient receiving high-dose prednisone therapy.

[A simple vital microscopy aid for the detection of scabies mites]. / Eine einfache vitalmikroskopische Hilfe zum Nachweis von Skabiesmilben.

By means of a convenient and inexpensive incident light microscope, the mite of sarcoptes scabiei in vivo can be easily detected in the skin. This method simplifies the search for mites especially in children, because it allows to investigate many papules and probable burrows quickly and without pain.