Evaluation of Ivermectin vs Permethrin for Treating Scabies-Summary of a Cochrane Review

Comparison of topical permethrin 5% vs. benzyl benzoate 25% treatment in scabies: a double-blinded randomized controlled trial

BACKGROUND

Scabies is a pruritic parasitic infestation of the skin. High-income countries have reported an increasing incidence over the last few years. Studies have indicated a reduction in the sensitivity of scabies mites to the standard treatment of choice, topical permethrin 5%.

OBJECTIVES

To evaluate in a head-to-head manner the efficacy of two topical scabicides [permethrin 5% and benzyl benzoate 25% (BB)] in the treatment of scabies using the same administration modality; and to address potential confounding factors such as incorrectly performed treatment and hygiene measures.

METHODS

In total, 110 patients with dermoscopy-verified scabies infestation were enrolled and randomized into two equally sized groups in a double-blinded manner. Fifty-five received topical permethrin 5% and 55 received topical BB 25%, both for daily use over a period of three consecutive days. Treatment outcome was evaluated by dermoscopy at a 3-week follow-up visit.

RESULTS

Treatment resulted in a dermoscopy-verified cure rate of 27% in the permethrin group and 87% in the BB group. The tolerability and safety profile of permethrin 5% cream was excellent, while the BB emulsion produced a burning sensation in 43% of patients.

CONCLUSIONS

Topical permethrin demonstrated a lack of efficacy in the majority of scabies cases, whereas BB demonstrated an excellent cure rate and reasonable tolerability. Considering the reduced sensitivity of scabies mites to permethrin 5%, our results suggest that BB is an appropriate first-line therapy in the treatment of scabies.

National survey in Switzerland calls for improved diagnosis and treatment in children with scabies

AIM OF THE STUDY

The global prevalence of scabies is estimated to be up to 200 million cases annually, with young children particularly affected. In Europe, most cases are thought to originate in migrant populations. Scabies management is challenging in children. To identify knowledge gaps and research needs, we aimed to descriptively evaluate the management of children with scabies by different Swiss healthcare providers.

METHODS

An invitation for an anonymous online survey (36 questions) was sent to members of Swiss societies of dermatologists, general practitioners, paediatricians, paediatric dermatologists, paediatric infectious diseases specialists, and tropical medicine specialists, inviting clinicians to participate from 25th May to 8th August 2020. One reminder invitation was sent. Hospital pharmacies and the distributor of permethrin were contacted to report consumption trends of scabicides in 2018 and 2019.

RESULTS

The survey was completed by 248 clinicians: 146 (59%) paediatricians, 47 (19%) dermatologists, 28 (11%) general practitioners, 6 (2%) paediatric dermatologists, 13 (5%) paediatric infectious diseases specialists, and 8 (3%) tropical medicine specialists. Most consulted up to 10 scabies cases within a 16-month period, with similar numbers in migrant and Swiss children. Dermoscopy was used by 24% of non-dermatologists. Non-dermatologists did not consider co-treatment of close contacts in up to 59% of cases. While permethrin was the first-line treatment, treatment failures were frequently reported in children aged <5 years. Up to 67% of paediatric dermatologists regularly used oral ivermectin off-label in children weighing <15 kg. None of the paediatric dermatologists, 15% of the dermatologists, and 9% of the non-dermatologists used only one treatment cycle.Scabicide consumption increased. Treatment studies on ivermectin use in children weighing <15 kg had the highest research priority.

CONCLUSION

In Switzerland, scabies is a frequent dermatosis in migrant and Swiss children. While accessible, optimal diagnostics are underutilised, and treatment is suboptimal. Permethrin resistance appears to be an increasing problem. Dermatologists regularly use ivermectin off-label in children weighing <15 kg. Treatment studies on ivermectin use in children weighing <15 kg, user-friendly diagnostic tools, new treatment protocols, and child-friendly dosage forms are needed to improve the diagnosis and treatment of children with scabies.

Tratamiento de la escabiosis

La escabiosis afecta a más de 200 millones de personas en el mundo, y ocasiona un importante impacto socioeconómico. El mecanismo de contagio es por contacto directo prolongado. El contagio por fómites es infrecuente, aunque puede ser importante en la sarna noruega. La terapia con permetrina tópica al 5% es recomendada como tratamiento de primera línea. Puede indicarse durante el embarazo y la lactancia, y parece ser segura en niños < 2 meses. Sin embargo, últimamente se ha reportado una disminución de la efectividad de este fármaco. Otra alternativa en primera línea terapéutica es la ivermectina oral. Se puede administrar durante la lactancia, y estudios recientes sugieren que es segura en niños y lactantes pequeños. Diversas revisiones sistemáticas y metaanálisis han concluido que la ivermectina oral es tan efectiva y segura como la permetrina tópica. La administración terapéutica «en masa» de ivermectina oral es una excelente opción para el manejo de escabiosis en comunidades con alta prevalencia o de brotes en instituciones.

Management of common scabies and postscabetic itch in adults: Lessons learned from a single-center retrospective cohort study

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Combined topical permethrin plus oral ivermectin treats common scabies

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Patients 55 years or older may be more likely to experience post-scabetic itch

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Post-scabetic itch may persist for a median of 52.5 days (interquartile range, 28-135)

Background

Common scabies can be difficult to diagnose and treat. There are limited data on the clinical characteristics of patients who may benefit from combined topical permethrin plus oral ivermectin. Postscabetic itch is common, but there is scant data describing its prognosis and management.

Objective

This study describes the clinical characteristics and evaluates treatment outcomes of participants with common scabies treated with combined topical permethrin plus oral ivermectin and describes the prognosis and management of postscabetic itch.

Methods

We conducted a single-center retrospective cohort study of participants with common scabies treated with combined topical permethrin plus oral ivermectin therapy and topical permethrin only. Participants previously treated with permethrin and/or ivermectin were excluded. The primary outcome was clinical outcome at follow-up, categorized as cure, worsening, or no change. Secondary outcomes included time from treatment initiation to cure, duration of follow-up after cure, recurrence rate, frequency of postscabetic itch, and duration of postscabetic itch.

Results

Of 55 participants treated with combined topical permethrin plus oral ivermectin, 49 (89%) achieved cure, 5 (9%) had no change, and 1 (2%) had worsening disease. Of 48 participants treated with topical permethrin only, 46 (96%) achieved cure, 2 (4%) had no change, and 0 (0%) had worsening disease. Thirty-five participants (34%) experienced postscabetic itch for 52.5 days (interquartile range, 28–135). More participants in the older (mean: 55 years; standard deviation: 21 years; p = .002) combined treatment group experienced postscabetic itch than in the younger (mean: 42 years; standard deviation: 19 years) permethrin-only treatment group (42% vs. 25%; p = .072).

Conclusion

These findings support the use of combined topical permethrin plus oral ivermectin therapy in treating common scabies, highlight that postscabetic itch can persist for longer than previously reported, and reveal a potential relationship between older age and postscabetic itch.

Scabies: Epidemiology, Diagnosis, and Treatment

BACKGROUND

Scabies is a skin infestation whose incidence is apparently rising.

METHODS

This review is based on pertinent articles retrieved by a selective search of PubMed on diagnosis and treatment strategies.

RESULTS

Thread-like papules (burrows), new, intense pruritus, and dermatitis guide the suspected diagnosis which is confirmed by the microscopic or dermatoscopic demonstration of scabies mites. The first line therapy is topical application of permethrin, in accordance with the current recommendations for its use. Other treatment options include systemic ivermectin and topical crotamiton or benzyl benzoate. A combination of permethrin and ivermectin is used to treat otherwise intractable cases and is generally indicated for the treatment of crusted scabies. Known causes of treatment failure include improper application of the external agents, failure of repeated treatment with ivermectin, incomplete decontamination of furnishings and clothes, failure to simultaneously treat contact persons, absence of written documents explaining treatment modalities, and the patient's belonging to a risk group. Even though there has not yet been any direct proof of resistance of scabies mites to permethrin, there is a rising number of welldocumented cases of poor response to this agent. Moxidectin is a new substance now undergoing clinical testing.

CONCLUSION

Treatment of scabies according to the guidelines and the additional recommendations reported here should result in effective curing, even in cases that are thought to be intractable.

Control of scabies in a tribal community using mass screening and treatment with oral ivermectin -A cluster randomized controlled trial in Gadchiroli, India

Background

Scabies is often endemic in tribal communities and difficult to control. We assessed the efficacy of a community-based intervention using mass screening and treatment with oral ivermectin in controlling scabies.

Methods/ Findings

In this cluster randomised controlled trial, 12 villages were randomly selected from a cluster of 42 tribal villages in Gadchiroli district. In these villages, trained community health workers (CHWs) conducted mass screening for scabies. The diagnosis was confirmed by a physician. Six villages each were randomly allocated to the intervention and usual care arm (control arm). In the intervention arm (population 1184) CHWs provided directly observed oral ivermectin to scabies cases and their household contacts. In the usual care arm (population 1567) scabies cases were referred to the nearest clinic for topical treatment as per the standard practice. The primary outcome was prevalence of scabies two months after the treatment. Secondary outcomes were prevalence of scabies after twelve months of treatment and prevalence of impetigo after two and twelve months of treatment. Outcomes were measured by the team in a similar way as the baseline. The trial was registered with the clinical trial registry of India, number CTRI/2017/01/007704.

In the baseline, 2 months and 12 months assessments 92.4%, 96% and 94% of the eligible individuals were screened in intervention villages and 91.4%, 91.3% and 95% in the usual care villages. The prevalence of scabies in the intervention and usual care arm was 8.4% vs 8.1% at the baseline, 2.8% vs 8.8% at two months [adjusted relative risk (ARR) 0.21, 95% CI 0.11–0.38] and 7.3% vs 14.1% (ARR 0.49, 95% CI 0.25–0.98) at twelve months The prevalence of impetigo in the intervention and usual care arm was 1.7% vs 0.6% at baseline, 0.6% vs 1% at two months (ARR 0.55, 95% CI 0.22–1.37) and 0.3% vs 0.7% at 12 months (ARR 0.42, 95% CI 0.06–2.74). Adverse effects due to ivermectin occurred in 12.1% of patients and were mild.

Conclusions

Mass screening and treatment in the community with oral ivermectin delivered by the CHWs is superior to mass screening followed by usual care involving referral to clinic for topical treatment in controlling scabies in this tribal community in Gadchiroli.

Scabies is a skin infestation caused by a mite. It leads to disabling itching and sometimes serious bacterial infections. Scabies is endemic in tribal communities. Skin creams and lotions are available to treat scabies but patients may not apply them thoroughly. We conducted a controlled trial in 12 villages to test if an oral medicine called Ivermectin can reduce scabies in a tribal community in central India. In six randomly selected villages (control arm), trained community health workers (CHWs) screened for scabies, physician confirmed the diagnosis and referred patients to the nearest clinic for treatment with skin creams. In the remaining six villages (intervention arm) the patients of scabies and their contacts were provided supervised treatment with oral ivermectin by the CHWs after the diagnosis. Number of scabies cases were evaluated at two and twelve months after these treatments. The risk of scabies was reduced by 79% and 51% at the end of two and twelve months in villages where oral Ivermectin was used compared to villages where patients were referred to receive skin creams. Adverse reactions due to Ivermectin were mild. Screening of individuals and treating scabies with oral Ivermectin by CHWs can be a useful method to reduce scabies in tribal communities.

[Development of an ivermectin-containing syrup as an extemporaneous preparation for treatment of scabies in children]

BACKGROUND

Oral ivermectin can be used to treat scabies. Evidence for safe and effective use in young children in individual treatment situations has been developed and published. In order to also ensure a body weight-adapted dosage for children, an ivermectin-containing syrup was developed as an extemporaneous preparation.

MATERIALS AND METHODS

Since ivermectin is not available as a pure substance for the formulation, tablets containing active ingredient were used as a basic material for development. The formulation was designed according to pharmaceutical, regulatory and use-oriented criteria. An HPLC (high-pressure liquid chromatography) method was developed and validated to demonstrate chemical stability. In order to facilitate the practical implementation, information on suitable packaging material and application aids was also developed and the formulation was evaluated.

RESULTS

It has been demonstrated that the final formulation produced in the pharmacy was stable and can be stored for 3 weeks. No concerns were raised regarding the tolerability of the syrup formulation. The physicochemical properties and the taste of the formulation allow the intended use as a well-dosed syrup for children.

CONCLUSION

The developed formulation meets the requirements of the Apothekenbetriebsordnung (Pharmacy Work Rules; Section 7 ApBetrO) and enables an exact, body weight-adapted dosage of oral ivermectin in young children. Studies on human pharmacokinetics or clinical studies to demonstrate tolerability and/or efficacy are not available for the formulation.

Intervention protocol to improve scabies control in enclosed communities: a case report

OBJECTIVES

To describe patients with scabies in a prison setting. Document what type of treatment was carried out. Prepare an intervention protocol to improve scabies control in the Penitentiary Center.

MATERIAL AND METHOD

All cases of scabies diagnosed in the Youth Detention Centre (La Roca del Vallès, Barcelona) between November 2018 and November 2019 were recorded. The treatment used was recorded. Bibliographical research on the protocols and treatment guidelines was carried out for community-acquired scabies.

RESULTS

The study was performed with 762 inmates, of whom 61 patients were diagnosed with scabies. 39 patients' pathologies were detected at the time of admission to the center, 11 cases were diagnosed in the first 6 weeks after entering the prison, coinciding with the incubation period of the disease. Finally, 11 more were diagnosed when they had already been in prison for more than 6 weeks and therefore could be infected cases within the center. This parasitosis was detected mainly in inmates of North African origin, 14.7% of Algerian inmates and 14.2% of Moroccan inmates presented this pathology, compared to 1.6% among Spanish prisoners. All 61 patients were treated with permethrin and 8 cases had to repeat the treatment cycle due to apparent therapeutic failure. Research literature indicates that oral ivermectin should be the drug of first choice for the treatment of scabies in prison.

DISCUSSION

The high incidence of scabies cases detected in prison led us to carry out a bibliographic review that brought about changes in the treatment protocol that may be of interest for the control of the disease in closed communities.