## **Core Concept**
The question describes a scenario suggestive of scabies, a contagious skin infestation caused by the mite *Sarcoptes scabiei*. Scabies is known for causing intense itching and a pimple-like skin rash. The fact that all family members are affected indicates a high likelihood of scabies due to its contagious nature.

## **Why the Correct Answer is Right**
The drug of choice for treating scabies is **permetrin cream**. Permethrin is a topical cream that works by killing the scabies mites and their eggs. It is considered safe for use in children and adults, making it an ideal choice for treating scabies in an 8-year-old boy and his family members. Its effectiveness and safety profile make it a preferred option over other treatments.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Ivermectin, while used for scabies, is typically reserved for more severe cases or when topical treatments are not feasible or have failed. It's not usually the first line of treatment for uncomplicated scabies.
- **Option B:** Cetirizine is an antihistamine used to relieve allergy symptoms such as runny nose, sneezing, itchy or watery eyes, hives, and itching. It does not treat the underlying cause of scabies.
- **Option C:** This option is not provided, but typically, other treatments like lindane have been used but are less preferred due to potential neurotoxicity.
- **Option D:** This option is not provided, but other topical treatments or oral medications might be considered in certain cases but are not the first line.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that scabies treatment requires simultaneous treatment of all family members and close contacts, even if they are asymptomatic, to prevent re-infestation. Permethrin cream is generally applied from the neck down in children and left on for 8-14 hours before being washed off.

## **Correct Answer:** . Permethrin cream