## **Core Concept**
Scabies is a skin infestation caused by the mite *Sarcoptes scabiei*. Treatment aims to eliminate the mite and alleviate symptoms. Oral medications are considered when topical treatments are not feasible or effective.

## **Why the Correct Answer is Right**
Ivermectin is an antiparasitic drug effective against a wide range of parasites, including *Sarcoptes scabiei*. It works by interfering with the parasite's nervous system, leading to paralysis and death. Ivermectin has been shown to be effective in treating scabies, particularly in cases where topical treatments like permethrin are not suitable or have failed.

## **Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because without specifying the drug, it's impossible to assess its relevance to scabies treatment.
* **Option B:** This option is incorrect for the same reason as Option A; the drug is not specified.
* **Option C:** This option is incorrect as it is not recognized as a primary treatment for scabies.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that ivermectin is particularly useful in institutional outbreaks of scabies or in patients with crusted scabies, where topical treatments may not be practical. A single dose of ivermectin may be sufficient, but sometimes a second dose is needed.

## **Correct Answer:** . Ivermectin