Anti-mite and louse medications

Mites and lice are arthropod ectoparasites, (or external parasites), that live on the surface of the body, like the skin or hair.

Ectoparasiticides are topical medications used to treat these infestations.

Endectocides on the other hand, are multi-purpose antiparasitics that work on both external parasites and some internal parasites, like roundworms.

Now, lice are wingless insects that live off of the blood of their hosts.

There are 3 types of lice that infest humans: head louse that lives in the hair of the scalp; body louse that lives in the hair of the axilla, back, and pubic region; and pubic louse, also called crab louse, that lives in pubic and axillary hair, but also the eyebrows.

Lice infestation is called pediculosis and the main symptom is pruritus, (or itchiness), which is caused by an allergic reaction to louse’s saliva.

Scratching of the bites could also lead to bacterial skin infections.

Another common ectoparasite is the Sarcoptes scabiei mite which causes scabies.

These tiny critters are eight-legged arthropods that are related to spiders.

Unlike spiders, scabies mites burrow into the skin and cause a pimple like rash locally.

Even worse, they tunnel around under the skin, forming elevated tracks that are visible on the skin surface.

The burrowing causes intense itching that’s more frequent at night when the mites are more active.

The most common sites for scabies are between the fingers, on the flexor surface of the wrist, and the extensor surface of the elbow and knees.

They can also be found around the areola of the breast and the pubic region.

Permethrin is an ectoparasiticide and an insecticide. It’s the first line medication for both scabies and pediculosis.

This medication is used topically in the form of creams, lotions, or shampoos.

Once taken in by the parasite, permethrin binds to sodium channels on the membrane of neurons, and prolongs their inactive state. This results in delayed repolarization, leading to respiratory muscle paralysis and death.