Scabies is an infestation caused by the mite Sarcoptes scabiei. These mites burrow into the skin and cause the infected person to develop allergic inflammation, leading to redness and itching. These insects can infect both humans and animals, with cases of this disease in almost every country in the world. It is estimated to affect over three hundred million individuals worldwide, spreading rapidly in places of high population density and crowding.[1,2]
Conventional treatment includes insecticides such as ivermectin, selamectin, permethrin, and benzyl benzoate. They have shown to be effective but the scabies mite can become resistant to treatments like permethrin and ivermectin.[3-5] Plant-derived insecticides have been studied in search of an efficient, low toxic, and environmentally friendly alternative. Plant-based oils can be infused into carrier oils, that when applied topically may provide relief from these types of infections. Promising research exists on the following traditional herbal treatments.
Tea Tree Oil
Melaleuca alternifolia has been used in traditional medicine for bruises, insect bites, and skin infections. One study that subjected S Scabiai to various components demonstrated 5% tea tree oil (TTO) as being effective at killing scabies. 5% TTO cut the median survival time of mites in half compared to the same concentration of permethrin and was found to be better than ivermectin. Although tea tree oil has mite killing activity, no human clinical trials exist for the use of tea tree oil for scabies. Many laboratory studies show great promise for the effects of TTO on scabies, and a single field trial exists reporting a 98.5% resolution of scabies in a population of pigs just after four weeks of treatment using just two applications of 1% TTO a week apart.
Cinnamomum camphora, the fragrant camphor tree has been valued for its uses since ancient times. Camphor is widely used as a fragrance, flavoring, and common topical analgesic. Camphor exhibits many different properties, which includes its ability to be insecticidal. Occurring naturally in Asian countries, the essential oil is distilled from the wood and can be used additionally for pain relief for minor muscle aches.[9,10] One study recorded in the Journal of the Egyptian Society of Parasitology against the scabies mite found that camphor oil in concentrations as low as 50% dilution gave way to a complete cure within five to ten days.
Azadirachta indica is a popular traditional herbal medicine, native to India. Neem has been used largely for its antifungal, antibacterial, antiparasitic, and anti-inflammatory properties. Recent studies have examined the mechanism of an active constituent found within the oil extract demonstrating potent insecticidal properties with small concentrations. One pilot study, employing neem and turmeric combined in a paste for the treatment of scabies on 814 people, recorded a 97% efficacy obtained within three to fifteen days of initiation. Though no human clinical trials exist, shampoos containing neem seed extract and crude neem seed kernel extracts have shown efficacy in studies on animals.[14,15]
Eupatorium adenophorum is perennial herb, found in Central and Latin America, with distribution in other tropical and temperate regions. The extract has been used traditionally throughout Vietnam for many years for skin infections. One study on rabbits infected with scabies demonstrated that two treatments of topically applied 0.5g/ml solutions of Boneset were equivalent to conventional treatment. No mites were present in the toes in the group on day 14, which confirmed the efficacy of the extract as comparable to ivermectin.
Proceed with caution when using essential oils. Camphor, for example, is poisonous when ingested and can cause seizures, confusion, irritability, and muscular hyperactivity. More research is needed to further indicate the safety of these plants and consultation with a medical provider is highly recommended before applying any topical treatment with a toxic profile. High concentrations of potent herbal ointments, lotions, solutions, suspensions, creams, pastes, gels all have the capability of causing contact dermatitis. Using a carrier oil to deliver topical treatments in the appropriate dosages is required to prevent adverse side effects.