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.     

Scabies

Scabies is an ectoparasite caused by the mite Sarcoptes scabiei var hominis , an obligate human parasite. There are about 300 million cases of scabies in the world each year. Common predisposing factors are overcrowding, immigration, poor hygiene, poor nutritional status, homelessness, dementia, and sexual contact. Direct skin-to-skin contact between 15 and 20 minutes is needed to transfer the mites from one person to another. The diagnosis suspected with a clinical history of itch, worse at night, affecting other family members, clinical distribution, and appearance. Definite diagnosis relies on microscopic identification of the mites, eggs, or fecal pellets with 10% potassium hydroxide, ink enhancement, tetracycline fluorescence tests, or mineral oil; other methods include: epiluminescence light microscopy and S. scabiei DNA. The most commonly used treatment modalities are permethrin and ivermectin. Persistence of symptoms for 2–6 weeks after successful treatment is common. Most recurrences are because of reinfection from untreated contacts.     

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.     

Variable response of crusted scabies to oral ivermectin: report on eight Egyptian patients

Background  Several reports have proved the efficacy of oral ivermectin in the treatment of crusted scabies. However, the response varied greatly between different studies.
Objective  The aim of this study was to evaluate the response of crusted scabies to oral ivermectin in eight Egyptian patients.
Patients and Methods  Eight patients with crusted scabies, diagnosed clinically and confirmed microscopically, were involved in this study. Patients received a single oral dose of ivermectin (200ug/kg) and re-examined at 2, 4, 6 and 8 weeks. A second dose of ivermectin was given in case of treatment failure at the end of the second week. A third dose of ivermectin, combined with permethrin 5% and salicylic acid 5% was given at the end of the fourth week for the nonresponders to the second dose.
Results  Two patients were completely cured after a single dose of ivermectin, 4 patients required a second dose at a 2-week interval to achieve cure and 2 patients cleared from scabies after the combined therapy. No recurrence was reported at the end of 8 weeks. An inverse relation was observed between the response to ivermectin and the severity of immunosuppression, crust thickness and mite burden.
Conclusion  Oral ivermectin is an effective alternative therapy for the treatment of crusted scabies. The response of crusted scabies to oral ivermectin is variable and combination therapy with topical scabicides and keratolytics seems to be the best choice.     

Treatment of scabies: Comparison of permethrin 5% versus ivermectin

Scabies is an ectoparasitic, highly contagious skin disease caused by a mite called Sarcoptes scabiei. The insecticides ivermectin and permethrin are commonly used for treatment of scabies. This study aimed at comparing the efficacy of oral ivermectin with topical permethrin in treating scabies. Two hundred and forty-two patients with scabies attending the dermatology outpatient department of Sina Hospital, Tabriz University of Medical Sciences were admitted. Patients were divided into two groups randomly. The first group and their family contacts received 5% permethrin cream and the other received oral ivermectin. Treatment was evaluated at intervals of 2 and 4 weeks. A single dose of ivermectin provided a cure rate of 85.9% at a 2-week interval, which increased to 100% after crossing over to the permethrin group at a 4-week interval. Twice application of permethrin with a 1-week interval was effective in 92.5% of patients, which increased to 94.2% after crossing over to the ivermectin group at a 4-week interval. Permethrin-treated patients recovered earlier. Twice application of permethrin with a 1-week interval is superior to a single dose of ivermectin. The temporal dissociation in clinical response suggests that ivermectin may not be effective against all the stages in the life cycle of the parasite.     

Behandlung der endemischen Skabies mit Allethrin, Permethrin und Ivermectin Evaluation eines Behandlungskonzeptes

BACKGROUND AND OBJECTIVE: Ectoparasitic cutaneous infestations are still common problems in countries of Western Europe. Scabies is a highly contagious disease of the skin caused by Sarcoptes scabiei variatio hominis. It has a world-wide distribution and affects all ages with no specific gender predisposition.Scabies is of profound public health interest because certain environment factors such as overcrowding, poor hygiene, delayed treatment of primary cases and lack of public enlightenment are conducive to its spread. However, prompt and adequate therapy is rewarding and prevents further spreading. Scabies acquires additional public health significance when large numbers of individuals are affected, as in a nursing home.Outbreaks of scabies in such dimensions require a special treatment strategy. PATIENTS/METHODS: On request of the town council an eradication concept for the treatment of endemic scabies in nursing and retirement homes was developed. RESULTS: persons (IP) and identification of the likely index patients (IXP)because of their widespread disease should be the first step of an eradication program. All IP except for IXP should be treated irrespective of clinical signs by a single application of a modern effective external scabicide such as allethrin (Spregal) or permethrin cream (permethrin 2,5% until 6th year of life or permethrin 5% in a hydrophilic cream) at day 1 (day X).The following 10-day quarantine and close control of all IP is an inexpensive and safe method of eradication. IXP are admitted and treated with oral administration of single dose of ivermectin, which can be repeated on day 8 if necessary. In addition permethrin cream 5% can be applied in severe cases, combined with nail trimming and aggressive cleaning of the subungual debris. Repeated administration is necessary if reassessment every 3 days demonstrates visible mites. (Note: none of this is mentioned in German.) The staff is instructed to wear gloves during all patient contact. CONCLUSIONS: Our strategy for eradication of endemic scabies has proven effective. Allethrin can be used following the package inpermethrin is more effective and can also be used in children, as well as pregnant and nursing women. Ivermectin is particularly useful in treating crusted scabies. It is not approved for scabies in Germany so the patients must be accordingly counseled.The frequency and the major therapeutic problems in treating endemic scabies make it important to work for the approval of permethrin and ivermectin in this setting.     

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.     

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.     

Management of endemic outbreaks of scabies with allethrin, permethrin, and ivermectin

BACKGROUND: At three residences for the elderly, recurrent scabies infestations became out of control. Due to the failure of repeated, nonsynchronized therapeutic efforts with conventional external anti-scabies treatments, an eradication program had to be developed. We describe a protocol for the management of outbreaks of scabies. METHODS: According to the clinical examination and microscopically identified mites, all individuals of the population (IOP: patients, staff, and family members) were divided into two groups: (a) healthy and infested IOP; and (b) cases with crusted scabies. The first group was treated simultaneously once with external scabicides (allethrin or permethrin). All others were hospitalized and treated either with systemic ivermectin or with the latter in combination with permethrin. RESULTS: In 252 IOP living in three residences for the elderly, clinical signs of scabies were reported in 91.5%, 78.5%, and 15.4% of the patients (age 55-97 years; mean, 80.5 years), 54.1%, 32.9%, and 16.6% of staff members, and in 7%, 3%, and 0% of family members. The infested IOP showed crusted scabies (index cases) in 5.3%, 5.0%, and 1.7%, common scabies in 43.1%, 36.7%, and 7.1%, and postscabiotic dermatitis in 10.3%, 7.6%, and 3.5%. In 99.2% of the synchronously treated IOP in group (a) (n = 240), the conventional treatment with permethrin cream 5% or allethrin spray was effective. Group (b) (n=12) received ivermectin (12 mg) once (n=5) or twice (n= 7) after an interval of 8 days. One index case received permethrin three times. CONCLUSIONS: Outbreaks of scabies in populations of elderly people require special management for disease control. Synchronous treatment with external permethrin cream 5% or allethrin spray, including all IOP once, and close control offers a time-saving, cheap, and reliable method. Crusted scabies should be treated by oral administration of ivermectin once or twice after an interval of 8 days. Additional applications of permethrin and mechanical clearing of hyperkeratotic subungual areas shorten the course.     

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.     

Psoriasis or crusted scabies

We describe a case of a 67-year-old woman with a 1-year history of nail thickening and a non-itchy erythematous scaly eruption on the fingertips. She was diagnosed with psoriasis and started on methotrexate after having had no response to topical calcipotriol. The diagnosis was reviewed after it was revealed by another consultant that the patient's husband had been attending dermatology clinics for several years with chronic pruritus, which had been repeatedly thought to be due to scabies. Our patient was found to have crusted scabies after a positive skin scraping showed numerous mites. She was treated with topical permethrin, keratolytics and oral ivermectin. We also review the literature on crusted scabies and its management, with recommendations.     

Crusted scabies in an adult T-cell leukemia/lymphoma patient successfully treated with oral ivermectin

We report an adult T-cell leukemia/lymphoma (ATL) patient whose crusted scabies was successfully treated with oral ivermectin. This 63-year-old man had previously been treated with oral prednisolone, sobuzoxane and etoposide for approximately 1 year. When he developed crusted scabies, he received two doses of oral ivermectin (200 microg/kg) 10 days apart and the concomitant topical application of crotamiton containing 30% benzyl benzoate. This produced remarkable results, suggesting that oral ivermectin should be considered for the treatment of crusted scabies even in immunocompromised patients. While ivermectin may be useful for treating intractable scabies, attention must be paid to the possible appearance of ivermectin-resistant mites.     

Successful use of ivermectin in the treatment of endemic scabies in a nursing home

Ivermectin, an antiparasitic agent, was successfully used as a sole agent to combat endemic scabies in a closed 33-bed ward of a rural nursing home. Previous topical therapies, including multiple applications of permethrin, -γ-benzene hexachloride, benzyl benzoate and precipitated sulfur in white soft paraffin, had failed. Several patients exhibited hyperkeratotic crusted scabies with head and neck involvement and all residents except one recently arrived resident had evidence of active infestation. All residents were treated with 200 μg/kg of ivermectin and this dose was repeated 2 weeks later in all subjects. Four weeks after the first dose of ivermectin there was no evidence of active scabies and all rashes were totally resolved by 6 weeks. The action of ivermectin, its safety and its indications are discussed.     

Tinea pseudoimbricata caused by M. gypseum associated to crusted scabies

Tinea pseudoimbricata is related to T. tonsurans and T. rubrum and crusted scabies is a highly contagious dermatosis caused by excessive proliferation of S. scabiei var. hominis. We described a case of a 21-year-old patient, seronegative for HIV, with both skin diseases. The occurrence of these dermatosis simultaneously in immunocompetent patients is very rare.     

Oral ivermectin treatment in two cases of scabies: effective in crusted scabies induced by corticosteroid but ineffective in nail scabies

We report two cases of scabies treated with oral ivermectin (200 micro g/kg). Case 1, a 72-year-old man, developed crusted scabies with the use of oral corticosteroids due to a misdiagnosis by an earlier physician. The patient was successfully treated with two doses of oral ivermectin at a 7 day interval with concomitant topical use of crotamiton and keratolytic agents. However, the nail scabies in this patient failed to respond to these treatments. Live mites were detected from all his toenails two weeks after the second dose of ivermectin. A complete cure of the nail scabies was achieved by occlusive dressing of 1% gamma-BHC on all toenails for one month. Case 2, a 52-year-old woman, had been treated with oral corticosteroid for mesangial nephritis. She developed common scabies, but a topical scabicide, crotamiton, was not effective. Two weeks after treatment with a single dose of oral ivermectin, eggs were still detected from a burrow on her trunk. Her treatment was completed after a further two doses of oral ivermectin were administered at 7 day intervals. In both patients, the administration of oral ivermectin did not induce any clinical or laboratory side effects. Oral ivermectin is effective for crusted scabies, but not effective for nail scabies. Two doses of oral ivermectin, administered with a one-week interval, is an appropriate treatment regimen.     

Tackling scabies: novel agents for a neglected disease

The scabies mite, Sarcoptes scabiei var hominis, is an obligate ectoparasite of humans. It has been a source of distress for humanity since antiquity. The troublesome mite is emerging triumphant over current acaricidal agents with reports of emerging resistance and treatment failures. Scabies in endemic areas and crusted scabies offer additional management challenges. Exploration of indigenous plants and better understanding of mite biology and pathogenesis provide opportunities for the development of novel agents for this common pest. We review the recent diverse approaches to scabies, including the use of novel plant products with a better safety profile, translating the use of moxidectin from veterinary practice to human scabies, vaccination, immunotherapy, and development of drugs that directly target mite molecules.     

Polarizable elements in scabies infestation: a clue to diagnosis

The diagnosis of scabies infestation is straightforward in cases where mite parts are largely visible; however, mites are often not captured in a specimen's planes of section. Polariscopic examination is a fast and simple adjunctive diagnostic tool to light microscopy. We describe the unique polariscopic findings in scabies infestation. Two cases of crusted scabies and eight cases of typical scabies were subjected to polariscopic examination. Diagnostic mite parts were visualized in at least one section in all cases. Attached and detached spines as well as scybala (fecal material) are polarizable. Specifically, spines show a polarizable outer sheath with dark central core while scybala show peripherally concentrated, stippled birefringence. Similar stippled birefringence is visible within the gut of some mites whereas significant birefringence is not appreciated in other mite parts. These results suggest that polariscopic examination is a helpful clue in the diagnosis of scabies infestation, especially in cases where the body of the mite is not visualized.     

Efficacy and tolerance of oral ivermectin in scabies

Objective The aim of this open-label study was to investigate the therapeutic effect and adverse reactions of oral ivermectin in scabies patients.
Background There is much confusion over reports of efficacy, adverse reactions and relapses after oral treatment of scabies with ivermectin.
Methods Nineteen patients, ten otherwise healthy outpatients with scabies, and nine inpatients with scabies and another skin disease (dermatomyositis, 3; pemphigus, 2; bullous pemphigoid, 1; pyoderma, 1; HIV, 1; Behcet's disease, 1) were treated with an oral dose of 0.2 mg/kg ivermectin (1% water solution) on days 1 and 8. The presence of live mites and ova in the patient's skin was investigated before, during and after the treatment.
Results None of the 19 patients with scabies had evidence of scabies after the second dose of ivermectin. In seven patients we noted the enhancement of pruritus 24–72 h after the first administration of ivermectin. In three patients the skin manifestation, vesicle-pustular rash increased between the second and the fourth day.
Conclusion The advantages of oral ivermectin treatment in scabies patients are: high therapeutic efficacy against Sarcoptes scabiei , good tolerance and influence of the drug on the whole skin surface and on clinical symptoms. The administration of the drug is easy and quick.     

Localised genital Norwegian scabies in an AIDS patient

OBJECTIVES: We present a case of an AIDS patient with Norwegian scabies manifest by a single, crusted plaque localised to the glans penis. METHODS: A 45 year old man with AIDS presented to our clinic complaining of a red papular pruritic rash on his abdomen and anterior thighs and a single, thick, crusted, non-pruritic lesion on the penis. He had been treated with lindane topically prior to the development of the penile lesion without resolution of the pruritus or red papular lesions. A mineral oil preparation was obtained from the hyperkeratotic penile lesion and revealed numerous mite eggs and faeces. RESULTS: The diagnosis of localised, genital Norwegian scabies was made. The patient was treated with ivermectin 200 micro g/kg per dose taken as two doses, 14 days apart, with complete resolution of both pruritus and skin lesions. CONCLUSIONS: This patient is the first known report of Norwegian scabies localised as a single lesion on the penis. He was successfully treated with oral ivermectin monotherapy.     

Terpinen-4-ol, the main component of Melaleuca alternifolia (tea tree) oil inhibits the in vitro growth of human melanoma cells

The search for innovative therapeutic approaches based on the use of new substances is gaining more interest in clinical oncology. In this in vitro study the potential anti-tumoral activity of tea tree oil, distilled from Melaleuca alternifolia, was analyzed against human melanoma M14 WT cells and their drug-resistant counterparts, M14 adriamicin-resistant cells. Both sensitive and resistant cells were grown in the presence of tea tree oil at concentrations ranging from 0.005 to 0.03%. Both the complex oil (tea tree oil) and its main active component terpinen-4-ol were able to induce caspase-dependent apoptosis of melanoma cells and this effect was more evident in the resistant variant cell population. Freeze-fracturing and scanning electron microscopy analyses suggested that the effect of the crude oil and of the terpinen-4-ol was mediated by their interaction with plasma membrane and subsequent reorganization of membrane lipids. In conclusion, tea tree oil and terpinen-4-ol are able to impair the growth of human M14 melanoma cells and appear to be more effective on their resistant variants, which express high levels of P-glycoprotein in the plasma membrane, overcoming resistance to caspase-dependent apoptosis exerted by P-glycoprotein-positive tumor cells.