What is the recommended treatment for scabies?

Scabies Treatment

Topical permethrin 5% cream applied from the neck down for 8-14 hours is the first-line treatment for uncomplicated scabies, with oral ivermectin 200 μg/kg (repeated in 2 weeks) as an effective alternative. 1, 2

First-Line Treatment Options

Topical Permethrin 5%

• Apply to all areas of the body from the neck down and wash off after 8-14 hours 3, 1, 2
• One application is generally curative, though a second application 7-10 days later is recommended to ensure eradication 3, 1
• More effective, safer, and less expensive than ivermectin for standard cases 3
• Recent evidence suggests applying permethrin as a cold cream (stored in refrigerator) once daily for two consecutive days may be more effective than single application, with 87.2% cure rate vs. 61.8% 4
• However, a 2024 head-to-head trial showed concerning results: permethrin achieved only 27% cure rate compared to 87% for benzyl benzoate 25%, suggesting potential resistance issues 5

Oral Ivermectin

• Dose: 200 μg/kg orally, repeated in 2 weeks 3, 1, 2
• Must be taken with food to increase bioavailability and penetration into the epidermis 3, 2
• Has limited ovicidal activity, making the second dose at 14 days essential 3, 2
• No dosage adjustments required for renal impairment, but safety of multiple doses in severe liver disease is unknown 3

Special Populations

Pregnant and Lactating Women

• Permethrin 5% is the preferred treatment 3, 1, 2
• Ivermectin should be avoided due to limited safety data in these populations 1, 6
• Permethrin is classified as Pregnancy Category B with no evidence of harm to the fetus 7

Infants and Children

• Permethrin is the treatment of choice for infants and young children 1, 2, 6
• Permethrin is safe and effective in children ≥2 months of age 7
• Ivermectin is contraindicated in children weighing <15 kg due to potential neurotoxicity 1, 6
• Lindane should never be used in children <10 years due to seizure risk 3, 1, 2

Crusted (Norwegian) Scabies

• Requires combination therapy: topical 5% permethrin cream applied daily for 7 days, then twice weekly until cure, PLUS oral ivermectin 200 μg/kg on days 1,2,8,9, and 15 1, 2

Alternative Treatments (When First-Line Fails or Is Contraindicated)

Lindane 1%

• Apply in thin layer from neck down and wash off after 8 hours 3
• Should only be used if patient cannot tolerate recommended therapies or if they have failed 3
• Absolute contraindications: children <10 years, pregnant/lactating women, extensive dermatitis, immediately after bathing 3, 1, 2
• Risk of neurotoxicity including seizures and aplastic anemia 3, 2
• Resistance reported in some areas 3

Benzyl Benzoate 25%

• Recent 2024 evidence shows 87% cure rate vs. 27% for permethrin 5
• May be considered when permethrin resistance is suspected 5
• Causes burning sensation in 43% of patients but has reasonable tolerability 5

Critical Management Considerations

Contact Management

• All persons with close personal, sexual, or household contact within the preceding month must be examined and treated simultaneously, even if asymptomatic 1, 2, 6
• Failure to treat all contacts simultaneously is the most common cause of treatment failure 6

Environmental Decontamination

• Machine-wash and machine-dry bedding and clothing using hot cycle, or dry clean 3, 1, 2
• Alternatively, remove items from body contact for at least 72 hours 3, 1, 2
• Fumigation of living areas is unnecessary 3, 1, 2

Follow-Up and Persistent Symptoms

• Pruritus, rash, edema, and erythema may persist for up to 2 weeks after successful treatment and do NOT indicate treatment failure 1, 2, 6, 7
• In clinical trials, approximately 75% of patients with persistent pruritus at 2 weeks had resolution by 4 weeks 7
• Consider retreatment only after 2 weeks if symptoms persist AND live mites are observed 1, 2, 6

Common Pitfalls to Avoid

Application Errors

• Failure to apply permethrin to all critical areas including under fingernails and to the edges of all body orifices 6
• Not applying to skin folds and creases where mites concentrate 3
• Using lindane immediately after bathing increases absorption and toxicity risk 3, 2

Treatment Protocol Errors

• Not repeating ivermectin dose at 2 weeks is essential for complete eradication 3, 6
• Expecting immediate symptom resolution leads to unnecessary retreatment 1, 2
• Treating the patient without simultaneously treating all household contacts 6

Special Considerations

• Immunocompromised patients require closer monitoring as they are at increased risk for treatment failure 2
• Secondary bacterial infections (especially Staphylococcus aureus and Streptococcus pyogenes) are common complications 8, 9
• Consider adding topical fusidic acid 2% for impetiginized scabies 9