What is the recommended treatment for scabies?

Scabies Treatment

Permethrin 5% cream is the first-line treatment for uncomplicated scabies, applied from the neck down for 8-14 hours, then washed off—one application is generally curative. 1, 2, 3

First-Line Treatment Options

Topical Permethrin 5% Cream

• Apply to all areas of the body from the neck down (including scalp in infants and young children), leave on for 8-14 hours, then wash off 1, 2, 3
• One application is typically curative for uncomplicated scabies 1, 3
• Preferred for pregnant/lactating women, infants, and young children due to excellent safety profile 2, 3
• Must include application under nails, all body folds, and up to the edge of all orifices to avoid treatment failure 1

Important caveat: Recent high-quality evidence from 2024 challenges permethrin's efficacy—a randomized controlled trial showed only 27% cure rate with permethrin vs. 87% with benzyl benzoate 25%, suggesting potential mite resistance 4. However, current CDC and AAP guidelines still recommend permethrin as first-line 2, 3.

Oral Ivermectin

• Dose: 200 μg/kg, repeated in 2 weeks 1, 2, 3
• Take with food to increase bioavailability and epidermal penetration 1, 2
• Not recommended for children weighing <15 kg due to potential neurotoxicity 3
• Limited safety data in pregnancy/lactation—avoid in these populations 3
• The second dose at 2 weeks is essential for complete eradication 1, 2

Special Populations and Situations

Crusted (Norwegian) Scabies

Requires combination therapy due to heavy mite burden: 1, 2, 3

• Topical 5% permethrin cream applied daily for 7 days, then twice weekly until cure 1, 2
• PLUS oral ivermectin 200 μg/kg on days 1,2,8,9, and 15 1, 2, 3
• This population has high infectivity and requires aggressive treatment 1

Immunocompromised Patients

• Closer monitoring necessary due to increased risk of treatment failure 2
• Consider combination therapy similar to crusted scabies approach 2

Alternative Treatments (When First-Line Options Unavailable)

• Benzyl benzoate 25% lotion: Apply for two consecutive days—recent evidence suggests superior efficacy to permethrin (87% vs. 27% cure rate) 5, 4
• Lindane 1%: Should be avoided due to neurotoxicity risk, especially in children <10 years, pregnant/lactating women, and persons with extensive dermatitis 1, 2, 3
• Sulfur 6-33% ointment: Alternative option with specific application instructions 2, 5

Critical Contact and Environmental Management

Simultaneous treatment of all contacts is mandatory—failure to do so is the most common cause of treatment failure: 1, 2

• Examine and treat all persons with close personal, sexual, or household contact within the preceding month, even if asymptomatic 1, 2, 3
• Decontaminate bedding and clothing by machine washing/drying on hot cycle, dry cleaning, or removing from body contact for at least 72 hours 1, 2
• Mites survive on clothing for up to 4 days without skin contact but only 1-2 days at room temperature 1
• Fumigation of living areas is unnecessary 2

Follow-Up and Persistent Symptoms

Rash and pruritus may persist for up to 2 weeks after successful treatment—this is NOT treatment failure: 1, 2, 3

• Approximately 75% of patients with pruritus at 2 weeks will have resolution by 4 weeks 6
• Retreatment is indicated ONLY if symptoms persist beyond 2 weeks AND demonstrable living mites are observed 1, 2, 3
• Persistent symptoms may also indicate reinfection from untreated contacts or fomites 2

Secondary Bacterial Infection

• Impetiginized scabies is commonly caused by Staphylococcus aureus and Streptococcus pyogenes 7
• Consider adding topical fusidic acid 2% cream if secondary bacterial infection is present—combination with permethrin 5% shows higher efficacy (95% vs. 35% at day 14) 7

Critical Pitfalls to Avoid

• Not treating all close contacts simultaneously—the leading cause of treatment failure 1, 2
• Inadequate topical application—must cover entire body surface including under nails and all body folds 1
• Using lindane after bathing—increases absorption and neurotoxicity risk 1, 2
• Not repeating ivermectin at 2 weeks—essential for complete eradication 1, 2
• Expecting immediate symptom resolution—pruritus normally persists up to 2 weeks post-treatment 1, 2, 6
• Misdiagnosing outbreaks—can lead to unnecessary mass treatment for "psychogenic" scabies 1
• Applying permethrin to eyes—flush immediately with water if contact occurs 6