Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the first-line treatment for scabies?

1. Permethrin 5% cream

2. Oral ivermectin

3. Topical benzyl benzoate

4. Crotamiton lotion

The correct answer is: Permethrin 5% cream

The first-line treatment for scabies is permethrin 5% cream, which is a topical insecticide effective against the mites that cause the condition. This treatment works by disrupting the nervous system of the scabies mites and leading to their death. It is widely recommended because of its effectiveness and favorable safety profile for use in various populations, including children and pregnant women. In contrast to other options, permethrin has a well-established protocol for application, typically requiring a single overnight application over the entire body (from the neck down), followed by washing off the cream after a specified duration. This method effectively addresses the infestation while also minimizing the risk of reinfestation. Other treatments, such as oral ivermectin, are generally reserved for cases that are more widespread or in specific circumstances like crusted scabies. Topical benzyl benzoate and crotamiton lotion are also used but are not considered first-line treatments due to lower efficacy compared to permethrin. Therefore, permethrin 5% cream is recognized as the most effective and preferred initial treatment for scabies.