Spinosad at 0.9% in the treatment of scabies: Efficacy results from 2 multicenter, randomized, double-blind, vehicle-controlled studies

Evaluation and Management of Pruritus and Scabies in the Elderly Population

Pruritus is the most common dermatologic complaint in the geriatric population. Its growing prevalence coincides with the rapid growth of the elderly population (>65 years of age) in the United States. According to the US Census Bureau, 16.9% of the population, or more than 56 million adults 65 years and older, lived in the United States in 2022. Pruritus is a condition that accompanies a diverse array of underlying etiologic factors. The mechanism of normal itch impulse transmission has been recently elucidated. The itch sensation originates from epidermal/dermal receptors connected to unmyelinated, afferent C-fibers that transmit the impulse from the periphery.

[Translated article] Epidemic Scabies: New Treatment Challenges in an Ancient Disease

Scabies which is among the most prevalent diseases worldwide, is becoming more frequent in Spain. The problems of this epidemic can be explained by several factors: improper application or prescription of treatments, resistance or reduced sensitivity to topical treatments, and poor understanding of the parasite and contagion. We require a new evidence-based approach to therapy that takes these problems into consideration. If symptoms persist after proper treatment, it is important to identify the reason for failure and standardize our approach. In refractory cases, the prescriber should prioritize oral medication, indicate a higher dose, combine treatments, or evaluate the use of off-label treatments in certain populations. The availability of new medications, such as spinosad or, especially, moxidectin, offer hope for bringing this disease under control.

Epidemic Scabies: New Treatment Challenges in an Ancient Disease

Scabies, which is among the most prevalent diseases worldwide, is becoming more frequent in Spain. The problems of this epidemic can be explained by several factors: improper application or prescription of treatments, resistance or reduced sensitivity to topical treatments, and poor understanding of the parasite and contagion. We require a new evidence-based approach to therapy that takes these problems into consideration. If symptoms persist after proper treatment, it is important to identify the reason for failure and standardize our approach. In refractory cases, the prescriber should prioritize oral medication, indicate a higher dose, combine treatments, or evaluate the use of off-label treatments in certain populations. The availability of new medications -such as spinosad or, especially, moxidectin- offer hope for bringing this disease under control.

Spinosad topical suspension (0.9%): a new topical treatment for scabies

INTRODUCTION

Scabies is a highly contagious skin disease caused by the parasitic mite Sarcoptes scabiei. There is no vaccine and for the past 30 years, the first line treatments have been topical permethrin and oral ivermectin. These drugs target mainly the parasite nervous system, killing only the motile stages. As they lack ovicidal activities, repeat treatments are required to achieve complete cure. Incompliance to repeat treatments causing prolonged drug usage, has contributed to emerging drug resistances. In addition, they are not appropriate for all patient categories, specifically for infants and young children or pregnant and breast feeding women. Consequently, new single dose scabicides are urgently needed.

AREAS COVERED

In 2021, spinosad, a drug previously used to treat head lice, was approved by the US FDA as a topical scabies treatment. Here the pharmacology, clinical efficacy and tolerability of this drug are discussed.

EXPERT OPINION

As the first single dose scabicide the formulated 0.9% topical Spinosad solution shows significant efficacy, little systemic absorption and no serious adverse reactions, making it a promising treatment for classical scabies in patients older than four years.

Two for One: Concurrent Acquisition of Molluscum Contagiosum Infection and Scabies Infestation After a Single Sexual Encounter

Molluscum contagiosum and scabies are contagious conditions that can be acquired by incidental casual contact of a disease-free individual with an infected person. However, both the viral infection and the mite infestation can be transmitted sexually from the infected person to the unsuspecting recipient partner. A 20-year-old man without any infectious diseases acquired not only molluscum contagiosum but also scabies after a single sexual encounter with a female partner; hence, he developed two sexually transmitted diseases after one sexual episode: two for one. He presented for medical attention to evaluate the new white umbilicated papules on his penile shaft and red nodules on the corona and glans of his penis. A complete skin examination also revealed additional papules on his abdomen and suprapubic region and a burrow on his left index finger adjacent to the finger web. Diagnosis of the molluscum contagiosum infection was confirmed by observing molluscum bodies on the molluscum preparation taken from an abdominal papule and the scabies infestation was confirmed by noting not only mite eggs but also mite scybala (feces) on the scabies (mineral oil) preparation from the burrow. The molluscum contagiosum infection was treated with curettage of the lesions. The scabies infestation was treated with two treatments (each one week apart) of permethrin five percent cream overnight topical application from his neck to his toes. All his lesions resolved and did not recur. In conclusion, the development of a new sexually transmitted disease in an individual should prompt the clinician to evaluate the patient for additional sexually transmitted diseases since the patient may have acquired more than one infection from their partner during the sexual encounter.