An ectoparasiticide is an

antiparasitic Antiparasitics are a class of medications which are indicated for the treatment of parasitic diseases, such as those caused by helminths, amoeba, ectoparasites, parasitic fungi, and protozoa, among others. Antiparasitics target the parasitic ...

drug used in the treatment of

ectoparasitic infestation An ectoparasitic infestation is a Parasitism, parasitic disease caused by organisms that live primarily on the surface of the host. Examples: * Scabies * Crab louse (pubic lice) * Pediculosis (head lice) * Gamasoidosis (avian mites) * ''Lernaeocer ...

s. These drugs are used to kill the parasites that live on the body surface.

Permethrin Permethrin is a medication and an insecticide. As a medication, it is used to treat scabies and lice. It is applied to the skin as a cream or lotion. As an insecticide, it can be sprayed onto outer clothing or mosquito nets to kill the insects ...

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

lindane Lindane, also known as ''gamma''-hexachlorocyclohexane (γ-HCH), gammaxene, Gammallin and benzene hexachloride (BHC), is an organochlorine chemical and an isomer of hexachlorocyclohexane that has been used both as an agricultural insecticide an ...

, dicophane,

benzyl benzoate Benzyl benzoate is an organic compound which is used as a medication and insect repellent. As a medication it is used to treat scabies and lice. For scabies either permethrin or malathion is typically preferred. It is applied to the skin as a l ...

ivermectin Ivermectin is an antiparasitic drug. After its discovery in 1975, its first uses were in veterinary medicine to prevent and treat heartworm and acariasis. Approved for human use in 1987, it is used to treat infestations including head lice ...

and

crotamiton Crotamiton is a drug that is used both as a scabicidal (for treating scabies) and as a general antipruritic (anti-itching drug). It is a prescription, lotion-based medicine that is applied to the whole body to get rid of the scabies mite that bur ...

are well known ectoparasiticides. Additionally, ectoparasiticides have been used to safely contaminate rhinoceros horns with hopes of it deterring the demand for these horns on the black market.

Variants

Permethrin

Broad-spectrum and potent pyrethroid insecticide and is most convenient for both scabies and lice. First choice drug. Permethrin exerts its therapeutic effect by disrupting sodium transport across neuronal membranes in arthropods, inducing depolarization. This mechanism ultimately leads to respiratory paralysis in the affected arthropod, establishing permethrin as a potent agent in managing scabies and pediculosis. Additional information about treatment failure rates amongst medications used to treat ectoparasites: https://www.dermatologyadvisor.com/news/scabies-treatment-failure-rates-increasing-among-children-and-adults/ The above research article, noted from current studies, shows that Permethrin is only 89.2% effective. There is noted resistance that has been increasing each year, as noted in the article.

Crotamiton

Second choice drug. Effective scabicide, pediculocide and antipruritic. Cure rate 60-88%.

Benzyl benzoate

2nd line drug for scabies and is seldom used for pediculosis. Cure rate 76-100%

Lindane

Effective in treating head lice (67-92%cure) and scabies (84-92% cure) with a single treatment. Penetrates through chitinous covers and affecting the nervous system.

Sulfur

Oldest scabicide and weak pediculocide, antiseptic, fungicide and keratolytic. Applied to skin, it is slowly reduced to H₂S and oxidized to SO₂ and pentathionic acid, which dissolve the cuticle of itch mites and kill it.

Ivermectin

Antihelminthic drug found highly effective in scabies and pediculosis. Acts through a glutamate-gated Cl⁻ ion channel found only in invertebrates.

Dicophan

Insecticide for mosquito, flies and other pests. Penetrates through the exoskeleton and acts as a

neurotoxin Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), insultsSpencer 2000 that can adversely affect function ...

Other Applications

Possible Poaching Deterrent

Ectoparasiticides have seen use as chemical agents in South Africa with the aim of devaluing rhinoceros horns and combating illegal poaching. Lorinda Hern, founder of the Rhino Rescue Project, devised a plan to infuse rhino horns with ectoparasiticides and mark the outer surface with a bright pink dye. This innovative approach seeks to deter poachers by creating health concerns amongst potential buyer communities. The procedure involves drilling into the rhinoceros horn, injecting it with an ectoparasiticide compound, and tagging it with a distinctive pink dye. The drill and inject procedure is considered harmless to the rhinoceros species due to the horn being isolated from both the nervous system and the bloodstream.

References

{{Ectoparasiticides Antiparasitic agents