Which scabicide is the drug of choice for scabies and is not associated with neurotoxicity?

• A. Lindane
• B. Crotamiton
• C. Sulfur ointment
• D. Permethrin

Answer: (D)

Permethrin is the scabicide of choice because it is highly effective against the mites and has a favorable safety profile with minimal systemic absorption, making neurotoxicity very unlikely at typical topical doses. It works by disrupting the parasite’s nerve membranes (voltage-gated sodium channels), causing paralysis and death of the mite, while humans are largely spared from serious neurological effects. This makes it suitable for a wide range of patients, including many who are pregnant or breastfeeding, and it is well tolerated with simple treatment regimens: apply to the entire body from neck down, leave on for about 8 to 14 hours, then wash off; treat close contacts and launder or seal items as needed. Some alternatives exist, like lindane, but it carries a real risk of neurotoxicity such as seizures, so it is avoided in favor of permethrin. Crotamiton and sulfur ointment are older therapies with lower efficacy or practical drawbacks, which is why they are not the preferred first-line choice.