Topical ivermectin: a new successful treatment for scabies

Ivermectin: A Multifaceted Drug With a Potential Beyond Anti-parasitic Therapy

Ivermectin was first discovered in the 1970s by Japanese microbiologist Satoshi Omura and Irish parasitologist William C. Campbell. Ivermectin has become a versatile pharmaceutical over the past 50 years. Ivermectin is a derivative of avermectin originally used to treat parasitic infections. Emerging literature has suggested that its role goes beyond this and may help treat inflammatory conditions, viral infections, and cancers. Ivermectin's anti-parasitic, anti-inflammatory, anti-viral, and anticancer effects were explored. Its traditional mechanism of action in parasitic diseases, such as scabies and malaria, rests on its ability to interfere with the glutamate-gated chloride channels in invertebrates and the lack of P-glycoprotein in many parasites. More recently, it has been discovered that the ability of ivermectin to block the nuclear factor kappa-light-chain enhancer of the activated B (NF-κB) pathway that modulates the expression and production of proinflammatory cytokines is implicated in its role as an anti-inflammatory agent to treat rosacea. Ivermectin has also been evaluated for treating infections caused by viruses, such as SARS-CoV-2 and adenoviruses, through inhibition of viral protein transportation and acting on the importin α/β1 interface. It has also been suggested that ivermectin can inhibit the proliferation of tumorigenic cells through various pathways that lead to the management of certain cancers. The review aimed to evaluate its multifaceted effects and potential clinical applications beyond its traditional use as an anthelmintic agent.

K, Baral A, Shrestha R, Shrestha R. Cutaneous larva migrans in a child: a case report and review of literature

Introduction

Cutaneous larva migrans (CLM) is a dermatitis caused by the invasion and migration of parasitic larvae of hookworms, primarily affecting tropical and subtropical regions. This report presents a case of CLM in a Nepali child and provides an overview of the literature on this condition.

Case report

A 4-year-old boy from a rural area in Nepal presented with a pruritic skin lesion on his left foot, initially misdiagnosed as fungal infection. The lesion gradually expanded, forming a serpiginous erythema, and became intensely pruritic. The patient's family had poor socioeconomic conditions, and the child frequently walked barefoot in an area with many domestic and stray dogs. Diagnosis was confirmed clinically, and treatment with oral albendazole and antihistamines resulted in complete resolution of symptoms.

Discussion

CLM is a neglected zoonotic disease, with an underestimated burden in developing countries due to underreporting and misdiagnosis. The larvae of Ancylostoma spp. are common culprits, causing a localized inflammatory reaction as they migrate through the skin. Diagnosis is mainly clinical and routine investigations usually reveal no abnormality. Complications may include secondary bacterial infections, allergies, and rare migration to internal organs. Treatment options include albendazole or ivermectin, with preventive measures emphasizing hygiene, footwear use, and pet deworming.

Conclusion

CLM is a neglected disease that primarily affects marginalized communities in tropical regions. Raising awareness among healthcare providers, conducting observational studies, and developing treatment guidelines, especially for children, are essential steps to address this public health concern. Preventive efforts, such as promoting hygiene and footwear use, should be encouraged to reduce CLM incidence.

Clinical interventions for tungiasis (sand flea disease): a systematic review

Tungiasis (sand flea disease) is an epidermal parasitic skin disease occurring in resource-limited communities. There is no standard treatment for tungiasis, and available treatment options are scarce. To our knowledge, this is the first systematic review aimed to assess randomised controlled trials (RCTs) investigating interventions for tungiasis. We systematically searched databases including MEDLINE (EBSCOhost), CENTRAL, CINAHL, PubMed, Web of Science, SciELO, LILACS and Embase (Scopus) for RCTs in any language, from inception of the databases until June 12, 2021. RCTs exploring preventive and therapeutic interventions for tungiasis were eligible. We used the revised Cochrane Collaboration's risk of bias tool to assess the risk of bias and Jadad scale to quantify the methodological quality of the RCTs. Of the 1839 identified records, only eight RCTs involving 808 participants were included, and several methodological deficiencies were identified in most of the trials. Trial interventions included: oral drugs niridazole and ivermectin and topical interventions of ivermectin lotion, metrifonate lotion, thiabendazole lotion, thiabendazole ointment, dimeticones (NYDA), and a neem seed and coconut oils-based mixture for treatment and coconut oil-based lotion (Zanzarin) for prevention. The coconut oil-based lotion for prevention and dimeticones for treatment of tungiasis have displayed the most promise. Most of the RCTs included in this study had low methodological quality. There is a clear unmet need for high-quality RCTs examining safe and effective prevention and treatment alternatives of tungiasis in endemic settings.

A narrative review of the roles of topical permethrin and oral ivermectin in the management of infantile scabies

As standard treatments are not licensed for use in the infantile population, the treatment of scabies in this age group can be challenging. We review the relevant evidence to determine the roles of topical permethrin and oral ivermectin in the management of infantile scabies. Demographic and clinical data were collected from relevant English articles published from January 2000 to December 2020. Complete resolution was observed in 100% of infants younger than two months treated with permethrin, and 87.6% of infants aged 12 months or less and/or children weighing under 15 kg treated with ivermectin. Adverse effects from permethrin use were limited to local eczematous reactions. Adverse effects from ivermectin use included mildly elevated creatine kinase levels, eczema flare-ups, diarrhoea, vomiting, irritability, pruritus and pustular skin reactions. Overall, both permethrin and ivermectin appear to have an acceptable safety profile in infants. Permethrin is highly effective as a first-line therapy for scabies in infants younger than two months. Ivermectin use is recommended when authorised topical treatment has failed, in crusted scabies, in cases where compliance with topical agents may be problematic, and in infants with severely inflamed or broken skin where prescription of topical therapies would likely cause cutaneous and systemic toxicity. Additional high-quality studies are needed to guide best practice in the management of infantile scabies.

Inhibition of Human Adenovirus Replication by the Importin α/β1 Nuclear Import Inhibitor Ivermectin

Human adenoviruses (HAdV) are ubiquitous within the human population and comprise a significant burden of respiratory illnesses worldwide. Pediatric and immunocompromised individuals are at particular risk for developing severe disease; however, no approved antiviral therapies specific to HAdV exist. Ivermectin is an FDA-approved broad-spectrum antiparasitic drug that also exhibits antiviral properties against a diverse range of viruses. Its proposed function is inhibiting the classical protein nuclear import pathway mediated by importin-α (Imp-α) and -β1 (Imp-β1). Many viruses, including HAdV, rely on this host pathway for transport of viral proteins across the nuclear envelope. In this study, we show that ivermectin inhibits HAdV-C5 early gene transcription, early and late protein expression, genome replication, and production of infectious viral progeny. Similarly, ivermectin inhibits genome replication of HAdV-B3, a clinically important pathogen responsible for numerous recent outbreaks. Mechanistically, we show that ivermectin disrupts binding of the viral E1A protein to Imp-α without affecting the interaction between Imp-α and Imp-β1. Our results further extend ivermectin's broad antiviral activity and provide a mechanistic underpinning for its mode of action as an inhibitor of cellular Imp-α/β1-mediated nuclear import.IMPORTANCE Human adenoviruses (HAdVs) represent a ubiquitous and clinically important pathogen without an effective antiviral treatment. HAdV infections typically cause mild symptoms; however, individuals such as children, those with underlying conditions, and those with compromised immune systems can develop severe disseminated disease. Our results demonstrate that ivermectin, an FDA-approved antiparasitic agent, is effective at inhibiting replication of several HAdV types in vitro This is in agreement with the growing body of literature suggesting ivermectin has broad antiviral activity. This study expands our mechanistic knowledge of ivermectin by showing that ivermectin targets the ability of importin-α (Imp-α) to recognize nuclear localization sequences, without effecting the Imp-α/β1 interaction. These data also exemplify the applicability of targeting host factors upon which viruses rely as a viable antiviral strategy.

Topical ivermectin-metronidazole gel therapy in the treatment of blepharitis caused by Demodex spp.: A randomized clinical trial

PURPOSE

To evaluate the efficacy of topical ivermectin-metronidazole combined therapy in the management of Demodex-associatedblepharitis.

METHODS

Sixty patients with a diagnosis of Demodex-associatedblepharitis were recruited in a randomized clinical trial. Thirty receiving topical ivermectin (0.1%)-metronidazole (1%) gel treatment on days 0, 15 and 30. Thirty additional patients were used as a control group receiving vehicle on days 0, 15 and 30. The primary efficacy measure was the number of Demodex spp. mitesin the eyelashes of patients. The secondary outcomes included clinical improvement of signs and adverse events.

RESULTS

Complete eradication of Demodex spp. was found in 96.6% of patients in the treatment group. Furthermore, a significant reduction of inflammation signs were found in all treated patients versus controls. None of the patients experienced any adverse effects associated with the treatment.

CONCLUSION

Demodex infection was controlled satisfactorily with the ivermectin (0.1%)-metronidazole (1%) gel, and no adverse effects were observed. Application of this gel for the treatment of different parasitic infections of the eyelids could be feasible, and this requires further exploration.

Update on parasitic dermatoses

These are cutaneous diseases caused by insects, worms, protozoa, or coelenterates which may or may not have a parasitic life. In this review the main ethological agents, clinical aspects, laboratory exams, and treatments of these dermatological diseases will be studied.

An unusual case of extensive truncal cutaneous larva migrans in a Cameroonian baby: a case report

BACKGROUND

Cutaneous larva migrans is a neglected zoonotic helminthic disease which is paradoxically underreported in low-income and middle-income countries from where a majority of the cases emanate. It presents as migratory, raised, erythematous serpentine lesions, responsive to treatment with antihelminthics. It is common in children, but rare in babies. We report an unusual case of cutaneous larva migrans in a Cameroonian baby.

CASE PRESENTATION

We report the case of a 9-month-old Cameroonian baby girl, whose mother had the habit of drying the child's clothes on the grass in her courtyard. The child was brought to our hospital after she developed itchy, snake-like, slowly progressing lesions on her abdomen and chest. An examination revealed multiple raised serpentine and erythematous skin lesions consistent with cutaneous larva migrans which subsided on antihelminthic and antihistaminic therapy.

CONCLUSIONS

Cutaneous larva migrans is an endemic disease with predilection for poor and vulnerable persons. Preventive efforts such as wearing of slippers, usage of drying lines, and deworming of pets are crucial in preventing the occurrence of this disease and should be encouraged.

Sarcoptic mange in wombats-A review and future research directions

Sarcoptic mange is caused by the mite Sarcoptes scabiei and has recently been recognized as an emerging infectious disease of wildlife worldwide. The mite is one of the main causes of population decline in southern hairy-nosed (Lasiorhinus latifrons) and bare-nosed wombats (Vombatus ursinus). This review focuses on Sarcoptes scabiei infestations in wombats and provides insights into why the disease may be so prevalent in wombats. Current treatment practices and trials conducted in the field to reduce the incidence of sarcoptic mange in wombats are described and critically reviewed. Current and potential future avenues of research are discussed.

Ivermectin inhibits porcine reproductive and respiratory syndrome virus in cultured porcine alveolar macrophages

Porcine reproductive and respiratory syndrome virus (PRRSV) is a devastating viral pathogen of swine that causes huge financial losses in the pig industry worldwide. Ivermectin is known to be a potent inhibitor of importin α/β-mediated nuclear transport and exhibits antiviral activity towards several RNA viruses by blocking the nuclear trafficking of viral proteins. Although PRRSV replication occurs exclusively in the cytoplasm of infected cells, the nucleocapsid (N) protein has been shown to distinctly localize in the nucleus and nucleolus throughout infection. Here, we sought to assess whether ivermectin suppresses PRRSV replication in cultured porcine alveolar macrophage (PAM) cells and to investigate the effect of ivermectin on the subcellular localization of the PRRSV N protein. Our data demonstrate that ivermectin treatment inhibits PRRSV infection in PAM-pCD163 cells in a dose-dependent manner. The antiviral activity of ivermectin on PRRSV replication was most effective when cells were treated during the early stage of infection. Treatment of PRRSV-infected cells with ivermectin significantly suppressed viral RNA synthesis, viral protein expression, and progeny virus production. However, immunofluorescence and cell fractionation assays revealed that ivermectin was incapable of disrupting the nuclear localization of the N protein, both in PRRSV-infected PAM-pCD163 cells and in PAM cells stably expressing the PRRSV N protein. This finding suggests that an alternative mechanism of action accounts for the ability of ivermectin to diminish PRRSV replication. Taken together, our results suggest that ivermectin is an invaluable therapeutic or preventative agent against PRRSV infection.

Topical ivermectin versus crotamiton cream 10% for the treatment of scabies

Scabies, known colloquially as the 7-year itch, is a contagious skin infection that occurs among humans and other animals. The treatment of choice is still controversial. The aim of this study was to compare the efficacy and safety of topical ivermectin vs. crotamiton cream 10% for the treatment of scabies. In total, 340 patients with scabies were enrolled, and randomized into two groups. The first group received 1% ivermectin applied topically to the affected skin. The dose employed was 400 μg/kg, repeated once the following week, and the second group received crotamiton 10% cream and were told to apply this twice daily for five consecutive days. Treatment was evaluated at intervals of two and four weeks, and if there was treatment failure at the 2-week follow-up, treatment was repeated. Two applications of topical ivermectin provided a cure rate of 64.7% at the 2-week follow-up, which increased to 82.3% at the 4-week follow-up after repeating the treatment. Treatment with single applications of crotamiton cream 10% was effective in 41.2% of patients at the 2-week follow-up, which increased to 64.7% at the 4-week follow-up after this treatment was repeated. Ivermectin was quite safe in our cases. Two applications of ivermectin were as effective as single applications of crotamiton 10% cream at the 2-week follow-up. After repeating the treatment, ivermectin was superior to crotamiton cream 10% at the 4-week follow-up.

Topical treatment of tungiasis: a randomized, controlled trial

Tungiasis is caused by the penetration of the female sand flea Tunga penetrans into the epidermis of its host. Human infestation with this ectoparasite is hyper-endemic in many resource-poor communities in sub-Saharan Africa, the Caribbean and South America and is associated with considerable morbidity. Currently, there is no effective drug available to treat tungiasis (or at least none for which a parasiticidal effect has been clearly demonstrated). In an attempt to fill this gap, the effects of treatment with topical ivermectin (lotion), thiabendazole (ointment and lotion), metrifonate (lotion) or placebo lotion were compared in a randomized trial. A total of 108 subjects with 169 tungiasis-infested feet participated in the study. The results show that topical ivermectin, metrifonate or thiabendazole can each significantly reduce the number of lesions caused by embedded sand fleas. Further studies are needed to optimise the doses and administration of these compounds.

[Urological dermatosis]

Urologists are often confronted with venereal and dermatological diseases during clinical evaluation of the external genitals. Dermatosis of the male genitalia ranges from infectious (viral and bacterial) lesions and inflammatory conditions to neoplastic alterations. There are also more general skin diseases (e.g. psoriasis) which occur as genital manifestations. In this case they often show unusual characteristics or the genitalia might be involved only incidentally. This review highlights the clinical diagnosis and therapy of the most common genital skin disorders and demonstrates the medical features.

Topical Ivermectin 0.5% Lotion for Treatment of Head Lice

Objective: To investigate the pharmacology, pharmacokinetics, efficacy, adverse effects, and place in therapy of a single application of topical ivermectin 0.5% lotion for head lice treatment. Data Sources: Literature was obtained by searching MEDLINE, PubMed, CINAHL, and Scopus (January 1980 to January 2013). Abstracts were searched for the terms ivermectin AND (head lice or pediculus or pediculosis), topical ivermectin, ivermectin lotion, ivermectin AND (pharmacology OR pharmacokinetics). The New Drug Application filed with the Food and Drug Administration and the product data sheets for ivermectin were obtained. Study Selection and Data Extraction: All English-language articles retrieved from the search were evaluated for relevance to the objective. Data Synthesis: The recommended first-line head lice treatments in the United States are permethrin 1% or pyrethrins, with malathion 0.5% lotion used as a second-line treatment. Significantly more of the 289 head lice–infested participants using topical ivermectin 0.5% lotion were lice-free at day 15 when compared with vehicle control (73.8% vs 17.6%; P < .001) in 2 studies. Although this rate is lower than other third-line treatments (eg, spinosad 0.9% or benzyl alcohol 5%), topical ivermectin 0.5% lotion is well tolerated (pruritus, the most common adverse event, 0.9%) and requires only a single application. Conclusions: Topical ivermectin 0.5% lotion kills head lice by increasing chloride in muscle cells, causing hyperpolarization and paralysis. Only 1 application is required; when the treated eggs hatch, the lice are not viable because they cannot feed as a result of pharyngeal muscle paralysis. Minimal systemic absorption occurs following topical application. Studies have demonstrated that topical ivermectin 0.5% is a safe and efficacious treatment for head lice. Although it has no documented resistance, there is limited clinical experience, it requires a prescription, and it is expensive. Therefore it should be reserved as a third-line treatment for head lice in the United States.

Ivermectin treatment for massive orbital myiasis in an empty socket with concomitant scalp pediculosis

We report a rare case of massive orbital myiasis following recent lid injury, occurring in the empty socket of an elderly lady, who had concurrent scalp pediculosis. The orbital myiasis was effectively treated with the broad-spectrum antiparasitic agent, ivermectin, thus precluding the need for an exploratory surgery. Ivermectin was also effective in managing the concurrent scalp pediculosis.

Ivermectin is a specific inhibitor of importin α/β-mediated nuclear import able to inhibit replication of HIV-1 and dengue virus

The movement of proteins between the cytoplasm and nucleus mediated by the importin superfamily of proteins is essential to many cellular processes, including differentiation and development, and is critical to disease states such as viral disease and oncogenesis. We recently developed a high-throughput screen to identify specific and general inhibitors of protein nuclear import, from which ivermectin was identified as a potential inhibitor of importin α/β-mediated transport. In the present study, we characterized in detail the nuclear transport inhibitory properties of ivermectin, demonstrating that it is a broad-spectrum inhibitor of importin α/β nuclear import, with no effect on a range of other nuclear import pathways, including that mediated by importin β1 alone. Importantly, we establish for the first time that ivermectin has potent antiviral activity towards both HIV-1 and dengue virus, both of which are strongly reliant on importin α/β nuclear import, with respect to the HIV-1 integrase and NS5 (non-structural protein 5) polymerase proteins respectively. Ivermectin would appear to be an invaluable tool for the study of protein nuclear import, as well as the basis for future development of antiviral agents.

ABC transporters influence sensitivity of Brugia malayi to moxidectin and have potential roles in drug resistance

Some ABC transporters play a significant role in human health and illness because they confer multidrug resistance (MDR) through their overexpression. Compounds that inhibit the drug efflux mechanism can improve efficacy or reverse resistance. Of the eight described ABC transporter subfamilies, those proteins conferring MDR in humans are in subfamilies A, B, C, and G. In nematodes, transporters in subfamilies B and C are suggested to confer resistance to ivermectin. The Brugia malayi ABC transporter superfamily was examined to assess their potential to influence sensitivity to moxidectin. There was an increase in expression of ABC transporters in subfamilies A, B, C, and G following treatment. Co-administration of moxidectin with inhibitors of ABC transporter function did not enhance sensitivity to moxidectin in males; however, sensitivity was significantly enhanced in females and microfilariae. The work suggests that ABC transporters influence sensitivity to moxidectin and have a potential role in drug resistance.

Scabies in healthcare settings

PURPOSE OF REVIEW

In industrialized countries, epidemics of scabies are mainly described within families or in institutions such as healthcare settings. Control of institutional scabies is associated with a considerable working and economic burden, but guidelines for the management are scarce.

RECENT FINDINGS

The prevalence of institutional scabies is probably underestimated. Identified risk factors for institutional scabies outbreaks include the institution type, extensive physical contact with patients and movement of patients, the existence of crusted scabies, a long diagnostic delay and failures in implementation of infection control or treatment plans.Atypical clinical features (hyperinfestation, scabies in the elderly or in children) may be misdiagnosed. Control of institutional scabies outbreaks relies on prompt recognition of the index case, constitution of an outbreak management team, determination of the extent of the outbreak and risk factors for spread, immediate implementation of infection control practices, adequate education of all involved persons, simultaneous treatment of cases and of all exposed individuals and concomitant environmental disinfection. Prolonged surveillance is imperative to eradicate scabies.

SUMMARY

The inclusion of institutionalized patients in randomized controlled trials would be beneficial as present data concerning scabicide effectiveness are obtained from trials that recruited individual participants and do not take into account a global strategy.

Scabies and pyodermas--diagnosis and treatment

Scabies and pyodermas are two of the commonest skin infections in tropical settings. They affect large numbers of people, particularly children, and account for a large burden of disease for peripheral health care teams. Despite this there have been significant advances in our knowledge of these diseases, their impact and their management. However there is a need to evaluate these developments in this specific setting, tropical health and in the context of communities with limited resources. This section will describe these advances and the challenges that remain.

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.

The Scourge of Sarcoptes: Oral Ivermectin for Scabies

OBJECTIVE

To review the use of the oral antiparasitic ivermectin in the treatment of scabies, with an emphasis on its use in the elderly and in long-term care settings.

DATA SOURCE

A MEDLINE/PUBMED search was conducted to identify pertinent studies, case reports, letters, and reviews in the English language. All articles published from 1980 to October 2003 were reviewed. Additional references were obtained from the bibliographies of these articles.

STUDY SELECTION

All studies evaluating ivermectin in the context of scabies mite infestation.

DATA SYNTHESIS

The semisynthetic macrocyclic lactone ivermectin has been available since the early 1980s as a broad-spectrum antiparasitic agent in animals and humans. This agent, which works by suppressing motor nerve conduction leading to parasite paralysis and death, was first used in ectoparasitic diseases (i.e., those caused by lice and mites) shortly after commercial introduction. A large body of literature, mainly uncontrolled case reports and series, has since evolved. However, these reports and results of the small number of placebo- and/or active-controlled studies have demonstrated the favorable response of both classic and crusted scabies to single- and multiple-dose oral ivermectin. Adverse reactions to the drug are uncommon, with the exception of a transient, new onset, or mild increase in existing pruritus soon after drug ingestion, which is thought to be a hypersensitivity reaction to dead mites and/or their products.

CONCLUSION

Oral ivermectin may prove to be a time- and labor-saving alternative to topical scabicide treatments, especially in the institutional setting where labor shortages make the management of scabies outbreaks a true challenge. However, the use of this agent does not change the need to decontaminate the environment (clothing, bedding, bed clothes, and, in selected cases, floors and walls) in order to truncate an outbreak and prevent reinfestation.

Interventions for treating scabies

BACKGROUND

Scabies is an intensely itchy parasitic infection of the skin caused by the Sarcoptes scabiei mite. It is a common public health problem with an estimated global prevalence of 300 million cases. Serious adverse effects have been reported for some drugs used to treat scabies.

OBJECTIVES

To evaluate topical and systemic drugs for treating scabies.

SEARCH STRATEGY

In February 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2006, Issue 1), MEDLINE, EMBASE, LILACS, and INDMED. In March 2007, we also searched the grey literature and sources for registered trials. We also checked the reference lists of retrieved studies.

SELECTION CRITERIA

Randomized controlled trials of drug treatments for scabies.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Results were presented as relative risks with 95% confidence intervals and data combined where appropriate.

MAIN RESULTS

Twenty small trials involving 2392 people were included. One trial was placebo controlled, 16 compared two or more drug treatments, two compared treatment regimens, and one compared different drug vehicles.Fewer treatment failures occurred by day seven with oral ivermectin in one small trial (55 participants). Topical permethrin appeared more effective than oral ivermectin (85 participants, 1 trial), topical crotamiton (194 participants, 2 trials), and topical lindane (753 participants, 5 trials). Permethrin also appeared more effective in reducing itch persistence than either crotamiton (94 participants, 1 trial) or lindane (490 participants, 2 trials). One small trial did not detect a difference between permethrin (a synthetic pyrethroid) and a natural pyrethrin-based topical treatment (40 participants). No significant difference was detected in the number of treatment failures between crotamiton and lindane (100 participants, 1 trial), lindane and sulfur (68 participants, 1 trial), benzyl benzoate and sulfur (158 participants, 1 trial), and benzyl benzoate and natural synergized pyrethrins (240 participants, 1 trial); all were topical treatments. No trials of malathion were identified. No serious adverse events were reported. A number of trials reported skin reactions in participants randomized to topical treatments. There were occasional reports of headache, abdominal pain, diarrhoea, vomiting, and hypotension.

AUTHORS' CONCLUSIONS

Topical permethrin appears to be the most effective treatment for scabies. Ivermectin appears to be an effective oral treatment. More research is needed on the effectiveness of malathion, particularly when compared to permethrin, and on the management of scabies in an institutional setting and at a community level.

A case of crusted scabies with a bullous pemphigoid-like eruption and nail involvement

We report a case of a 71-year-old man infected at a nursing home who developed a bullous pemphigoid-like eruption with nail involvement. He was diagnosed by his family doctor as suffering from eczema and was treated with topical corticosteroids, then blisters started appearing. He was next diagnosed as suffering from bullous pemphigoid and treated with oral prednisolone, which worsened his condition. He was finally diagnosed as having crusted scabies with bullous pemphigoid-like eruptions and nail involvement at our clinic. He was then prescribed oral ivermectin (two doses of 12 mg ivermectin with a 1-week interval) and topical lindane (1%gamma-BHC in petrolatum) for scabies with 5% salicylic acid in plastibase as an additional treatment for the crusted lesions on his soles. He showed remarkable improvement in 2 weeks, and his nails showed complete recovery after 7 weeks of occlusive dressing treatment with 1%gamma-BHC. One and a half years later, the patient showed no sign of a recurrence of scabies. The histology of a blister taken from this patient was similar to that of bullous pemphigoid. Direct immunofluorescence showed immunoglobulin (Ig)G and C3 deposition at the dermoepidermal junction similar to that of bullous pemphigoid, but indirect immunofluorescence was negative. The bullous symptoms of this patient were considered to be due to the scabies, because the patient recovered completely after receiving treatment for scabies. Indirect immunofluorescent study is important to distinguish between scabies with blister formation and true bullous pemphigoid.

Safety and efficacy of pediculicides for head lice

Head lice infestation is a common and growing problem, primarily affecting school-aged children. There are growing numbers of treatment failures due to the emergence of treatment-resistant lice to the popular over-the-counter products that have been used for the past several decades. Resistance has also decreased the efficacy of lindane, a prescription pediculicide that has been commonly used for several generations. Malathion, recently reintroduced in the US as a prescription pediculicide, has been associated with some treatment resistance depending upon its formulation. Other insecticidal treatments, such as ivermectin, will have to be developed further, given the limited options presently available for the treatment of head lice. Given the number of anecdotal and market-driven reported studies on head lice, assessment of topical lice therapies requires standardised in vitro testing. Based on concerns about safety and decreasing efficacy due to resistance, a reassessment of the general topic of pediculicides for head lice is warranted.

Scabies, pediculosis, bedbugs, and stinkbugs: uncommon presentations

Parasitic agents determine some of the most common skin disorders. Although well known, they could present different manifestations or be modified by individual or external factors that make their diagnosis or treatment difficult. This review will discuss some of the most prevalent parasitic infections, scabies, and pediculosis and also mention reactions determined by contact with certain insects that, although rarely found, could induce important skin reactions.

[Ivermectin]

Ivermectin is a semi-synthetic derivative of a macrocyclic lactone. It causes paralysis in many nematodes and arthropodes because of its effect on ion-channels in cell membranes. Ivermectin was first used in veterinary medicine. In man, it was shown to be microfilaricid against Onchocerca volvulus. Most of the adverse reactions following treatment were mild, without the systemic and ocular side effects usually complicating diethylcarbamazine therapy. In endemic areas after repeated administration of ivermectin, a dramatic reduction in dermal microfilarial load was observed, resulting in a decrease in transmission. There was a significant decrease in the prevalence of anterior segment lesions in the eyes and acute onchocercal skin disease. Moreover, ivermectin also exhibited microfilaricidal activity against Wuchereria bancrofti and Brugia malayi. Annual mass treatment with a single dose of diethylcarbamazine alone, or associated with ivermectin, was initiated in endemic areas for lymphatic filariasis. The preliminary results showed a decrease in the reservoir of microfilariae and rate of transmission, a reduction in the frequency of clinical lymphatic abnormalities due to bancroftan filariasis. In Loa loa infections ivermectin decreases microfilaremia, but serious adverse events such as encephalopathy can be induced in patients with high rate of microfilaremia. Ivermectin appears to be the drug of choice in Strongyloides stercoralis infections, a single dose is highly effective with less frequent side effects than thiabendazole. Oral ivermectin is an alternative to topical scabicides, it appears as effective as local treatment for common scabies, but there are few comparative studies. The best indications for ivermectin in this ectoparasitic infection could be the outbreak in institutions and crusty scabies, but in association with topical treatment. The precise position of this agent in the treatment of scabies remains to be specified. Ivermectin is also affective in the treatment of ascariasis and cutaneous larva migrans. It could also be a promising treatment for head lice.

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.

Ivermectin

Ivermectin is a potent antiparasitic drug and the first commercially available member of a new class of drugs (macrocyclic lactones) that has been approved for human use. Ivermectin has already proven to be highly effective in the elimination of river blindness as a public health burden. Side effects have been minor, and patient acceptance is good. Promising results in off-label applications for ectoparasitic infestations are increasingly important as resistance to topical therapy becomes more prevalent Ivermectin represents an advance in the therapeutic armamentarium and should be considered in appropriate cases.

Current treatments for scabies

Scabies is a frequent interhuman ectoparasitic infection. Several treatments are available worldwide. There are local treatments: synthetic pyrethrins, benzyl benzoate, lindane, crotamiton. Recently a few studies were published concerning ivermectin, systemic antiparasitic agent use in onchocercosis treatment. We reviewed the literature with an evidence-based medicine method. We attempt to answer two questions in particular: what is the treatment of choice for common scabies in a patient otherwise in good health? What is the role of systemic ivermectin? We also report specific situations. Among local treatments, studies are heterogeneous according to products, countries, group of treated patients, with or without contact subjects, and the method of treatment application. There are very few high proof-level controlled studies. In France, a combination of benzyl benzoate 10% and sulfiram 2% is used most, according to professional consensus. The most studied product is the cream permethrin 5%, available in the USA and UK. Its efficacy seems slightly superior to lindane and less toxic. It is more efficient than crotamiton. There is no study comparing benzyl benzoate and permethrin. Concerning systemic ivermectin, five controlled studies showed its efficiency in common scabies. But its relative efficiency over local treatment has not been established. A few open studies showed its efficacy in institutional epidemic, profuse scabies and in HIV-positive patients. Local treatment of choice in common scabies remains to be determined among the four principal molecules. There is no study comparing permethrin or esdepallethrin to benzyl benzoate. In what cases should we prescribe crotamiton or lindane? Indication of ivermectin seems proved in common scabies and probably for HIV-positive patients. It remains to be determined if it should be prescribed in the first instance, be double or triple, be associated or not with local treatment. In case of keratotic scabies, ivermectin seems interesting with two applications within 1 week, and should be associated with local treatment (duration remains to be defined). Ivermectin is probably useful in institutional epidemic, and therapeutic attitude remains to be defined. Ivermectin seems to have little or no risk. Treatment must be adapted case-by-case, according to feasibility. It is still important to treat contacts, and modality of this treatment remains to be specified.

Ectoparasitic infestations in homeless children

Most human ectoparasites live on the surface of their host and depend on that host to complete their life cycle. The most common ectoparasitic infestations of medical importance in humans include pediculosis, scabies, myiasis, and tungiasis. Different host factors are related, with increased risk of acquiring ectoparasitic infestation occurring among the homeless. Although these ectoparasitic infections can be found worldwide, their prevalence is affected significantly by environmental conditions in different geographical areas. This review focuses on the epidemiology, clinical presentation, diagnosis, and treatment of common ectoparasitic infestations among homeless children and their families. The most frequent bacterial infections associated with these infestations also are discussed.

Sulfur for scabies outbreaks in orphanages

Scabies outbreaks occurred in two large orphanages in Chiang Mai, Thailand. Since we were concerned about the availability, safety, and cost of scabicides in Thailand, sulfur in petrolatum was our choice for mass treatment of the children. We studied the efficacy of sulfur in children 2 months to 6 years of age. After the treatment, 47% and 71% of the 102 patients were cured in 2 weeks and 4 weeks, respectively. Only three preschool children developed a mild facial irritation after the first application. This agent is a safe and cheap choice for mass therapy.

Common skin disorders of the penis

Diseases of the male genitalia range from infectious lesions to inflammatory and neoplastic conditions, including many genital manifestations of more general skin diseases. This review highlights the clinical features, diagnosis and treatment of the most common dermatoses of the male genitalia. Herpes genitalis and infections caused by human papillomavirus (HPV) are increasing, particularly in young sexually active people. Herpes simplex virus infection is the commonest infectious cause of genital ulceration, with evidence that many infections are asymptomatic. HPV infection may be latent, subclinical and clinical. The most common causal agents for condyloma acuminatum are low-risk HPV 6 and 11; high-risk HPV types 16 and 18 are associated with premalignant and malignant lesions. Treatment for genital warts remains unsatisfactory; recurrences are common. Imiquimod, a new topical immunotherapeutic agent, which induces interferon and other cytokines, has the potential to be a first-line therapy for genital warts. Scabies and pediculosis are transmitted by skin-to-skin contact and sexual transmission is common, with the penis and scrotum favourite locations for scabious lesions. Oral ivermectin, a highly active antiparasitic drug, is likely to be the treatment of choice, but until approval is granted it should be reserved for special forms of scabies. Common skin diseases, e.g. psoriasis and lichen planus, may have an atypical appearance in the genital area. The typical psoriatic scale is usually not apparent because of moisture and maceration. Allergic contact dermatitis of the genital area may result from condoms, lubricants, feminine hygiene deodorant spray and spermicides. More often, contact dermatitis is irritant, resulting from persistent moisture and maceration. Lichen sclerosus is a chronic inflammatory disease that occurs as atrophic white patches on the glans penis and foreskin. The penile form is a common cause of phimosis in uncircumcised men; involvement of the urethral meatus may lead to progressive meatal stenosis. Plasma cell balanitis is a benign, idiopathic condition presenting as a solitary, smooth, shiny, red-orange plaque of the glans and prepuce of a middle-aged to older man. Squamous cell carcinoma (SCC) in situ, e.g. erythroplasia of Queyrat and Bowen's disease, cannot be excluded clinically; their apparent clinical benignity may lead to lengthy periods of misdiagnosis and biopsy is required to confirm the diagnosis. SCC is the most common malignancy of the penis and the role of oncogenic HPV-types has been also established in SCC of the penis. Prevention of SCC of the penis presupposes an identification of risk factors, early detection of all pre-cancerous lesions and treatment of phimosis.

Ivermectin is better than benzyl benzoate for childhood scabies in developing countries

OBJECTIVE

To compare single dose oral ivermectin with topical benzyl benzoate for the treatment of paediatric scabies.

METHODS

An observer-blinded randomized controlled trial was undertaken at Vila Central Hospital, Vanuatu. One hundred and ten children aged from 6 months to 14 years were randomized to receive either ivermectin 200 micro g/kg orally or 10% benzyl benzoate topically. Follow up was at 3 weeks post-treatment. Primary outcome measures were the number of scabies lesions, the itch visual analogue score and nocturnal itch. Secondary outcome measures were the skin's reaction to treatment, the passage of worms in stool and other side effects.

RESULTS

Eighty patients completed the study protocol. There was no significant difference between the two treatments; both produced a significant decrease in the number of scabies lesions seen at follow up. Ivermectin cured 24 out of 43 patients (56%), and benzyl benzoate 19 out of 37 patients (51%) at 3 weeks post-treatment. No serious side effects were noted with either treatment, but benzyl benzoate was more likely to produce local skin reactions (P = 0.004, OR 6.4, 95% CI 1.6-25.0)

CONCLUSIONS

Ivermectin is cheap and effective in the treatment of paediatric scabies. Ivermectin has minimal observed toxicity and has the additional beneficial effects of antiparasitic action in onchocerciasis, filariasis and strongyloidiasis. Ivermectin is better than benzyl benzoate for the treatment of paediatric scabies in developing countries.

Treatment of 18 children with scabies or cutaneous larva migrans using ivermectin

In addition to onchocerciasis and other filarial diseases, ivermectin has been used for the treatment of scabies, head lice, larva migrans and gnathostomiasis. However, there is concern regarding the safety of its use in children under 5 years of age or weighing less than 15 kg. We present our experience in 18 children (aged 14 months to 17 years), with scabies or cutaneous larva migrans successfully treated with ivermectin. They included four cases of crusted scabies associated with immunosuppression and seven cases of common scabies four of whom had associated clinical mental retardation, immunosuppression or hypomobility. A further seven patients had cutaneous larva migrans. Fifteen patients were cured with a single dose of ivermectin, and three patients with crusted scabies required a second dose. None of our patients suffered significant adverse effects. We believe that ivermectin is a safe and effective alternative treatment of cutaneous parasitosis in children.

Ivermectin in scabies

The standard treatment for scabies has long been based on topical scabicides. Ivermectin, a broad-spectrum anti-parasitic agent, was first used in veterinary medicine. This drug, active against nematodes and arthropods, is used in humans for the treatment of filariasis. For the past few years worldwide reports on the use of ivermectin in human scabies have suggested that this drug could be an alternative oral therapy.