Efficacy and safety of dimeticones in the treatment of epidermal parasitic skin diseases with special emphasis on tungiasis: an evidence-based critical review

ABSTRACT Epidermal parasitic skin diseases encompass scabies, pediculosis, cutaneous larva migrans, myiasis, and tungiasis. Tungiasis is probably the most neglected of all Neglected Tropical Diseases (NTD). It occurs in South America, the Caribbean and Sub-Saharan Africa and affects marginalized populations where people live in extreme poverty. In endemic communities the prevalence can be up to 30% in general population and 85% in children. Over time, chronic pathology develops characterized by hyperkeratosis, edema around the nail rim, fissures, ulcers, deformation and loss of nails. This leads to a pattern of disabilities, eventually resulting in impairment of mobility.Dimeticones are a family of silicon oils with a potential to kill parasites located on top or inside the epidermis by a physical mode of action. They are considered the treatment of choice for pediculosis capitis and pediculosis pubis. With regard to tungiasis, the so called rear abdominal cone of the parasites has been identified as a target for treatment with dimeticones. NYDA®, a mixture of two dimeticones with different viscosity, is the only dimeticone product for which data on the mode of action, efficacy and safety with regard to tungiasis exists. The product has been shown highly effective against embedded sand fleas, even in very intense infection with more than 500 parasites situated on top of each other. A randomized controlled trial showed that seven days after a targeted application of NYDA® 97% (95% CI 94-99%) of the embedded sand fleas had lost all signs of viability.Comprehensive toxicological investigations on the dimeticones contained in NYDA® showed that there is practically no risk of embryotoxicity, fetotoxicity, teratogenicity, and other toxicity. The safety of dimeticones was also demonstrated in clinical trials with a total of 106 participants with tungiasis, in which not a single adverse event was observed.

Disseminated tungiasis

Abstract: The authors report an unusual case of disseminated tungiasis in a 52-year-old patient living in the city of Campo Grande, state of Mato Grosso do Sul, who had crusted-papular-nodular lesions located in feet, hands, and right thigh. Diagnosis was confirmed by dermoscopy and anatomopathological examination.

Tungíase atualidades clínicas / Tungiase clinical news

O objetivo deste artigo é revisar as características clínicas da tungíase. A Tunga penetrans é a menor das pulgas conhecidas, alcançando 1 milímetro de comprimento quando atinge a fase adulta. Os relatos antigos de surtos de tungíase são escassos em relação aos registros epidemiológicos. O diagnóstico da doença é realizado através da história epidemiológica e dos achados clínicos, aliados ao exame direto com visualização do parasita, após abertura da lesão com agulha estéril. A retirada da pulga é o tratamento preconizado, sendo a profilaxia a melhor alternativa para controlar o parasita. Os profissionais de saúde devem atentar para a importância de se orientar as populações de áreas endêmicas em relação à doença, a fim de reduzir o número de casos e de complicações.

The purpose of this article is to review the clinical features of tungiasis. Tunga penetrans is the smallest known flea, reaching a millimeter in length when fully grown. The earliest accounts of outbreaks of tungiasis are scarce in relation to epidemiological records. The diagnosis is made by history and clinical epidemiological findings, coupled with the direct examination with visualization of the parasite after opening the wound with a sterile needle. The removal of the flea is the recommended treatment, and prophylaxis the best way to control the parasite. Healthcare professionals should be aware as to the importance of educating the public in endemic areas for the disease in order to reduce the number of cases and complications.

Tungiasis: Presentación de un caso clínico / Tungiasis: a case report

La tungiasis es una parasitosis cutánea originaria de América causada por Tunga penetrans. Se caracteriza por lesiones papulares, negruzcas, únicas o múltiples, que suelen afectar los pies, principalmente en las zonas subungueales y periungueales. El diagnóstico de tungiasis se realiza por las características clínicas de las lesiones en un paciente proveniente de zonas endémicas. El tratamiento de elección es la extracción quirúrgica de la pulga y la aplicación de antibióticos tópicos. Presentamos un caso de tungiasis en una paciente de 10 años de edad con múltiples lesiones en ambos pies, que fue tratada satisfactoriamente con ivermectina y extracción quirúrgica.

Tungiasis, is a cutaneous parasitosis, native of America caused by Tunga penetrans. Infestations usually presents with black papular lesions, either single or multiple, most of them localized on the feet, mainly in the subungual and periungual areas. Diagnosis of tungiasis is based on the characteristic aspect of the lesions in a patient coming from an endemic area. Surgical removal of the fea and application of a topical antibiotic is the standard treatment. We describe a case of a 10-years-old girl, with multiple lesions localized on feet, who was succesfully treated with ivermectin and surgical removal of lesions.