Skabies

Scabies is an infectious disease caused by Sarcoptes scabiei var. hominis. The disease is mainly transmitted by close personal contact. The primary clinical picture is characterized by burrows at typical areas as well as severe pruritus, while secondarily a rather non-specific exanthema can be observed. The detection of mites or mite products (eggs, feces) confirms the diagnosis; dermatoscopy may facilitate the diagnosis. First choice therapy for most variants of scabies is topical permethrin. Oral administration of ivermectin is recommended for some special indications. In the following article, the current knowledge about epidemiology, biology, immunology, clinical appearance, diagnostic procedures and therapy of scabies is reviewed.     

Grover's disease associated with Sarcoptes scabiei

An 83-year-old man presented with a 4-month history of discrete, itchy papules mainly distributed on the trunk and upper extremities. Histopathologic examination of two biopsies from lesions on the trunk revealed mainly focal suprabasal acantholysis and an inflammatory infiltrate composed mainly of lymphocytes with a few eosinophils. The overall clinical and histopathologic features were consistent with Grover's disease. However, scrapings taken from the skin lesions showed numerous mites of Sarcoptes scabiei. Subsequent treatment with an antiscabies cream led to a rapid complete cure, and no skin lesions have been observed during a 6-month follow-up. A review of the literature revealed 2 other cases of cutaneous lesions fulfilling the clinical and histopathologic features of Grover's disease in which mites of S. scabiei were demonstrated. Our observation further highlights the unusual association of Grover's disease with S. scabiei mites and emphasises the importance of excluding this easily treatable skin infestation in all patients with Grover's disease.     

Einseitig wandernde entzündliche filiforme Rötung an der Fußsohle

The goals of this German guideline are the improvement of diagnosis and therapy of scabies, the implementation of a coordinated action in outbreaks of scabies, and the control of this infestation in large migration or refugee flows.Sarcoptes scabiei var. hominis is transmitted by direct skin‐to‐skin contact of sufficient duration. The infectivity of female mites when removed from patients does not exceed 48 hours at room temperature (21°C) and relative humidity of 40‐80%. The risk of infection rises proportionally to the number of mites on the skin and is particularly high in crusted scabies. As elderly persons tend to develop crusted scabies due to disease‐ or medication‐related immunosuppression, there is an increased risk for outbreaks of scabies at nursing homes and extended‐care facilities. The guideline contains detailed recommendations for management of such outbreaks. In refugees the prevalence of scabies is higher than in the general population in Germany, but the risk for outbreaks is not high. Scabies infestation should be considered when a recent onset of itching is associated with eczema and presence of burrows or comma‐like papules at predilection sites. It is confirmed by dermatoscopic detection of mites or by microscopic identification of mites, mite eggs or fecal matter (scybala) from skin scrapings.The treatment of choice for common scabies is topical permethrin 5% cream applied for 8‐12 hours. Permethrin can be considered for off‐label use also in infants of less than 3 months of age and pregnant women. For this group crotamiton is another option, which, besides benzyl benzoate, presents a good second line therapy for the other indications. Indications for oral ivermectin, which has just been licensed in Germany, include patients with immunosuppression, severe dermatitis, and low adherence.Crusted scabies is preferentially treated by a combination of topical permethrin and oral ivermectin. Affected patients should be isolated, and all contact persons should be treated. The guideline contains lists for additional measures, including possible treatment of contact persons, clothes, linen and other possibly infested articles.     

Guideline for the diagnosis and treatment of scabies in Japan (second edition)

The guideline has been prepared by the Japanese Dermatological Association to ensure proper diagnosis and treatment of scabies, as oral therapy became available on August 2006 under health insurance and its clinical use was expected to increase. For making a proper diagnosis, the following three points should be taken into consideration: (i) clinical symptoms; (ii) detection of the mite (Sarcoptes scabiei); and (iii) epidemiological symptoms. The diagnosis is confirmed if the mites or eggs are identified by microscopy or dermoscopy and so forth. Topical sulfur preparations, with only limited usefulness, are the only available topical drugs approved by health insurance coverage for treating scabies. Currently, crotamiton, benzyl benzoate and gamma-benzene hexachloride are also used clinically. It is important to apply these to the whole-body, including hands, fingers and genitals. The dose for ivermectin is a single administration p.o. of approximately 200 microg/kg bodyweight with water before a meal. Administration of a second dose is considered, if new specific lesions develop or the mites are detected. For treating crusted scabies, concomitant administration of oral ivermectin and the topical preparation is necessary. Some safe and useful topical drug preparations are needed to be approved by health insurance.     

Pink pigtail in a skin biopsy: What is your diagnosis?

Sarcoptes scabiei is an obligate ectoparasite, which burrows into the stratum granulosum of the epidermis and lays its eggs. The resultant host inflammatory response leads to intensely pruritic papules. CASE SYNOPSIS: A 63-year-old man undergoing treatment for immunoproliferative disease was suspected of having a pruritic drug eruption. Subsequent skin biopsy revealed an intracorneal burrow containing three pink, refractile pigtail-like structures, believed to be empty eggshells of S. scabiei. CONCLUSION: Traditionally, the presence of adult mites or eggs in skin scrapings or a skin biopsy is required for a definitive diagnosis of scabies. However, our case and similar cases suggest that the diagnosis of scabies can also be made on the basis of pink pigtail-like structures, remnants of eggshells, within the intracorneal burrow.     

Human infestation by Sarcoptes scabiei var. bovis (cattle itch mite)

Infestation by Sarcoptes scabiei var. bovis in a farmer is reported. He presented with an intensely itching eruption of erythematous papules on forearm, neck and abdomen. An environmental investigation yielded that four of the farmer's cows had mange. Sarcoptes scabiei var. bovis was isolated from skin-scrapings of the cows. Histology from a self-induced lesion revealed that Sarcoptes scabiei var. bovis penetrates the human skin, but does not--in contrast to var. hominis--form burrows. This finding corresponds with the clinical picture. The mite lies subcorneally, compressing the thinned epidermis. The surrounding corneal tissue shows a marked exsudative reaction. The various ways in which mites may infest the human skin are discussed.     

Hidden scabies: diagnosis by polymerase chain reaction

Diagnosis of scabies infection can be difficult as in many cases only few mites are present on an infected person, and in some cases the skin manifestations can be subtle or atypical. We describe the use of polymerase chain reaction (PCR) to amplify Sarcoptes scabiei DNA in a patient presenting with clinically atypical eczema. Cutaneous scales were PCR positive for S. scabiei DNA before, and negative 2 weeks after, therapy. This method facilitates fast and very sensitive diagnosis of clinically atypical or inapparent scabies infection and therapy control in severely affected patients and may help to identify previously unrecognized scabies cases.     

Pseudoskabies durch Rotfuchs übertragen

Pseudoscabies, i.e. infestation of human skin with animal mites may occasionally occur and should be considered in the differential diagnosis of pruritic and papular skin disease. We report here on a 52-year-old woman with pseudoscabies or canine scabies (Sarcoptes scabiei var. canis), transmitted by indirect contact with a red fox in the urban area of Berlin. Red foxes may live in unhabited areas of metropolitan large cities, i.e. in garages, car wrecks and cellars. Full remission of the prolonged and pruritic rush was seen after topical administration of lindane together with systemic corticosteroids.     

Landwirtschaftliche Nutztiere als Vektoren von parasitären Epizoonoseerregern und zoophilen Dermatophyten

Different pest arthropods and dermatophytes occurring primarily in farm animals may be transmissible to man and produce human dermatoses. The movement and cutaneous penetration habits of external parasites often cause crusted papules, severe itching and dermatitis or may damage their hosts by blood-sucking or by sensitizing them to their saliva. Furthermore different dermatophytes should be considered a possible cause of human skin lesions. Farm animals (cattle, pig, poultry, and rabbit) can transmit external parasites (ticks: Ixodes ricinus, Argas reflexus; fleas: Ceratophyllus gallinae, Spilopsyllus cuniculi, and mites: Sarcoptes scabiei var. bovis, Sarcoptes scabiei var. suis, Dermanyssus gallinae, Cheyletiella parasitovorax), and dermatophytes (Trichophyton sp., and Microsporum sp.). People who have close contact to infested farm animals are more often exposed to epizoonotic infections. Certain professions, such as farmers, and veterinarians, are especially vulnerable.     

Pig Handler''s Itch

Forty-six humans who contacted pigs infested with Sarcoptes scabiei were investigated. Thirty (65.2%) had symptoms of sarcoptes scabies, and S. scabiei mites could be recovered from 20 (66.6%) skin scrapings. Itching was the main symptom. People within the age group of 26-35 years were infested the most. Hands and legs were the most common sites of the lesions, which subsided within 2-3 weeks when the infested pigs were treated and the intimate contact with the pigs was prevented.     

Acaricidal activity of Melaleuca alternifolia (tea tree) oil: in vitro sensitivity of sarcoptes scabiei var hominis to terpinen-4-ol

OBJECTIVE: To compare the acaricidal activity of Melaleuca alternifolia (tea tree) oil (TTO) and some of its individual active components on the itch mite Sarcoptes scabiei var hominis. DESIGN: In vitro acaricide sensitivity assessment. SETTING: The Menzies School of Health Research laboratory, located near the Infectious Diseases Ward of the Royal Darwin Hospital, Australia, where patients are admitted and treated for crusted scabies. PARTICIPANTS: Scabies mites (S scabiei var hominis) were collected from a 20-year-old Aboriginal woman admitted to the Royal Darwin Hospital with crusted scabies.Interventions Within 3 hours of collection, scabies mites were placed in continuous direct contact with the TTO products and control acaricides and were observed at regular intervals. MAIN OUTCOME MEASURES: Percentage of mites dead at regular observation intervals between 5 minutes and 24 hours during continuous exposure to the TTO products and acaricides. RESULTS: The 5% TTO and active component terpinen-4-ol were highly effective in reducing mite survival times. Statistically significant differences in mite survival curves were observed for 5% TTO, 2.1% terpinen-4-ol, 5% permethrin, and ivermectin (100 microg/g of Emulsifying Ointment British Pharmacopoeia 88). In vivo effectiveness was also observed. CONCLUSIONS: Documentation of resistance against antiectoparasitic compounds is increasing. Reported S scabiei treatment failures with lindane, crotamiton, and benzyl benzoate, as well as likely emerging resistance to 5% permethrin and oral ivermectin, are of concern and advocate for the identification and development of novel acaricidal drugs. Tea tree oil is a membrane-active biocide extracted from the tree M alternifolia. It is a principal antimicrobial in a wide range of pharmaceuticals sold in Australia, with the main active component being oxygenated terpenoids. The results suggest that TTO has a potential role as a new topical acaricide and confirm terpinen-4-ol as the primary active component.     

Diagnosis and Treatment of Scabies

Scabies is a common, highly pruritic infestation of the skin caused by Sarcoptes scabiei var. Hominis. It is a very contagious parasitosis with specific lesions, such as burrows, and nonspecific lesions, such as papules, vesicles and excoriations. The typical areas of the body it affects are finger webs, wrists, axillary folds, abdomen, buttocks, inframammary folds and, in men, the genitalia. It is characterized by intense nocturnal pruritus. Scabies is spread through close personal contact (relatives, sexual partners, schoolchildren, chronically ill patients and crowded communities). Definitive diagnosis is made when the scabies mites or their eggs or fecal pellets can be identified on a light microscope. New techniques for diagnosis include the use of the epiluminiscence microscopy. The most common topical treatments for scabies include lindane and permethrin. Permethrin provides a greater margin of tolerability because of its low inherent toxicity and low percutaneous absorption. Oral ivermectin is the most recently developed treatment for scabies. A single oral dose of ivermectin 200 microg/kg of bodyweight is a well-tolerated and very effective treatment. It is especially indicated in crusted scabies, scabies in immunocompromised hosts and infestations in crowded communities. It is also useful as a simple treatment in the prophylaxis of close contacts.     

Serum IgE Antibodies to the Scabies Mite

ABSTRACT: Porcine scabies, mites, Sarcoptes scabiei var. suis are more readily available in sufficient quantities than are human scabies mites. Circulating IgE antibodies specific to porcine scabies mites were found in 6 (30%) of 20 scabies patients with an RAST score of at least 2. Seven patients had elevated serum total IgE levels. Correlation between the RAST values, the duration of pruritus, and the IgE levels was not found. The results do not prove the existence of antibodies specific to porcine scabies mites but strongly support this assumption.     

Facial involvement in scabies in infancy

The infestation of a 3-month-old child with Sarcoptes scabiei by way of infested nipples during the breast-feeding period led initially to facial papules and later to generalized dermatitis. Scabies mites were not detected on the face; studies on ten infested babies in India supported this findings. Thus, direct antiscabies treatment to the face is not necessary in babies.     

Serum IgE Antibodies to the Scabies Mite

Abstract: Porcine scabies mites, Sarcoptes scabiei var. suis are more readily available in sufficient quantities than are human scabies mites. Circulating IgE antibodies specific to porcine scabies mites were found in 6 (30%) of 20 scabies patients with an RAST score of at least 2. Seven patients had elevated serum total IgE levels. Correlation between the RAST values, the duration of pruritus, and the IgE levels was not found. The results do not prove the existence of antibodies specific to porcine scabies mites but strongly support this assumption.     

Epidemic Norwegian scabies.

Norwegian scabies is an ectoparasitic infestation by Sarcoptes scabiei, characterized by hyperkeratotic lesions of the hands, feet, ears, and scalp, which contain many mites. An epidemic of Norwegian scabies involved 22 patients in a 25-patient ward of mentally and physically handicapped persons (mostly mongoloids). The pathogenesis of the prolific mite population is unclear, but either a specific immunologic deficit or the inability to effectively eliminate the mites by scratching is a plausible possibility.     

Dermestid Dermatitis in a 2‐Year‐Old Girl: Case Report and Review of the Literature

Dermatitis from contact with carpet, larder, and hide beetles (family Dermestidae) is a seemingly uncommon or underrecognized hypersensitivity reaction to the specialized hairs on the larvae of certain dermestid beetles. The erythematous papulovesicular dermatitis that may result from such contact can be mistakenly construed as evidence of bites of bedbugs or other arthropods or infestation with scabies mites or can be the basis for a diagnosis of delusory parasitosis. We present a case of dermestid dermatitis in a 2‐year‐old girl and provide a review of the current literature.     

Cross-antigenicity between the scabies mite, Sarcoptes scabiei, and the house dust mite, Dermatophagoides pteronyssinus.

This study demonstrated that antigens of the parasitic mite Sarcoptes scabiei (SS) cross-react with antigens of the house dust mite Dermatophagoides pteronyssinus (DP). Crossed immunoelectrophoresis (CIE) reaction of SS extract with rabbit anti-DP serum resulted in multiple immunoprecipitates. Reciprocal CIE reactions gave similar results. Immunoprecipitates from both reactions bound IgE in the sera of dust-mite-sensitive patients who had no history of scabies. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis resolved protein/peptide bands of both SS and DP also bound serum IgE from dust-mite-allergic patients following immunoblotting. Non-allergic control sera gave no IgE binding to either SS or DP antigens. These results indicate that patients with atopy to dust mites exhibit circulating antibodies built to DP but that recognize determinants on SS antigens. It is highly probable that scabietic patients build antibodies to SS antigens that also recognize DP antigens. These results raise questions concerning the reported isotypic antibody responses to SS because the sensitivity of scabietic patients to house dust mites has not been previously evaluated. This cross-reactivity may play an important role in the susceptibility to scabies and its clinical manifestations.     

What's eating you? Canine scabies

Infestation with Sarcoptes scabiei var canis, the causative strain of canine scabies, can produce a pruritic rash in humans. The rash generally manifests within 24 to 96 hours of contact with the affected pet. Scrapings are generally negative, and the correct diagnosis requires a high index of suspicion.     

Management of scabies

Scabies is a common contagious parasitic dermatosis. Transmission of the mite Sarcoptes scabiei var hominis generally occurs by skin-to-skin contact, but with crusted scabies it may also occur through fomites, such as infected clothing or bedding. Diagnosis is usually clinical. A 2010 updated Cochrane review concluded that management of scabies is based on topical scabicides, mainly 5% permethrin. However, oral ivermectin, although not licensed in many countries, may be useful, particularly for patients who cannot tolerate or comply with topical therapy and in institutional scabies epidemics. Patients should also receive detailed information about the infestation to limit further spreading. Cases resulting from close physical or sexual contact, even without symptoms, should be systematically treated. Hygienic measures should be taken after treatment is completed. Patients should be followed to confirm cure, including resolution of itching, which may take up to 4 weeks or longer.