Scabies: an ancient global disease with a need for new therapies

Abstract

BackgroundScabies is an ancient disease (documented as far back as 2500 years ago). It affects about 300 million people annually worldwide, and the prevalence is as high as about 60 % in Indigenous and Torres Strait Islander children in Australia. This is more than six times the rate seen in the rest of the developed world. Scabies is frequently complicated by bacterial infection leading to the development of skin sores and other more serious consequences such as septicaemia and chronic heart and kidney diseases. This causes a substantial social and economic burden especially in resource poor communities around the world.DiscussionVery few treatment options are currently available for the management of scabies infection. In this manuscript we briefly discuss the clinical consequences of scabies and the problems found (studies conducted in Australia) with the currently used topical and oral treatments. Current scabies treatment options are fairly ineffective in preventing treatment relapse, inflammatory skin reactions and associated bacterial skin infections. None have ovicidal, antibacterial, anti-inflammatory and/or anti-pruritic properties. Treatments which are currently available for scabies can be problematic with adverse effects and perhaps of greater concern the risk of treatment failure. The development of new chemical entities is doubtful in the near future. Though there may be potential for immunological control, the development of a vaccine or other immunotherapy modalities may be decades away.SummaryThe emergence of resistance among scabies mites to classical scabicides and ineffectiveness of current treatments (in reducing inflammatory skin reactions and secondary bacterial infections associated with scabies), raise serious concerns regarding current therapy. Treatment adherence difficulties, and safety and efficacy uncertainties in the young and elderly, all signal the need to identify new treatments for scabies.

Epidemiology, Diagnosis, and Treatment of Scabies in a Dermatology Office

“…3 Resistance to both oral ivermectin and topical permethrin has been described. 12 Of our study patients, 23% had received previous treatment for scabies before their initial evaluation at WFBMC; 18% of study patients required retreatment by WFBMC. The majority of these patients (68%) had been treated with permethrin alone; however, over a quarter of them had been treated with a combination of both permethrin and ivermectin.…”

Escabiose: Revisão e Foco na Realidade Portuguesa

“…5,7,9 Entre comunidades aborígenes australianas e na África subsariana a sua prevalência pode atingir os 10% (50% no caso das crianças). 4,5,9,14 Em 2013, a OMS adicionou a escabiose à lista das doenças tropicais negligenciadas. 9 Em países industrializados, surge habitualmente sob a forma de casos esporádicos ou epidemias em instituições, particularmente de idosos, e em grupos socialmente desfavorecidos.…”

“…4,5,9,14 Em 2013, a OMS adicionou a escabiose à lista das doenças tropicais negligenciadas. 9 Em países industrializados, surge habitualmente sob a forma de casos esporádicos ou epidemias em instituições, particularmente de idosos, e em grupos socialmente desfavorecidos. 1,5 Os principais fatores de risco são a pobreza, aglomerados populacionais (por exemplo, campos de refugiados), malnutrição e má higiene, e o atraso no diagnóstico e tratamento do caso índice.…”

“…27,28 Em certas comunidades, nomeadamente de aborígenes australianos, Índia, Chile e Trinidade, os surtos de GNA coincidem temporalmente com os de escabiose. 2,4,5,9 Outra complicação frequente é a eczematização resultante do ato de coçar ou do uso de produtos tópicos irritativos. 2,6 A escabiose pode levar ainda a uma estigmatização social, depressão, insónia, diminuição da concentração e significativos custos económicos, decorrentes do tratamento, consultas médicas frequentes e absentismo laboral.…”

“…8,9 Clinicamente pode variar de formas ligeiras a aparatosas, como no caso particular da variante crostosa, sendo as opções de tratamento relativamente limitadas. Para o sucesso terapêutico é essencial garantir a adesão do doente e dos contactos próxi-mos ao tratamento.…”