What is the recommended treatment guideline for scabies?

Scabies Treatment Guidelines

The recommended first-line treatment for scabies is permethrin 5% cream applied to all areas of the body from the neck down and washed off after 8-14 hours, or oral ivermectin 200 μg/kg, repeated in 2 weeks. 1

First-Line Treatment Options

Permethrin 5% Cream

• Application: Apply to all areas of the body from the neck down (consider scalp-to-toe application if head involvement is suspected) 2
• Duration: Leave on for 8-14 hours before washing off
• Efficacy: Most effective topical treatment with cure rates of 89-95% at 4 weeks 3
• Safety profile:
  • Pregnancy category B medication - safe for use during pregnancy 4
  • Safe and effective in children 2 months of age and older 4
  • May cause temporary exacerbation of pruritus, edema, and erythema 4

Oral Ivermectin

• Dosage: 200 μg/kg orally, repeated in 2 weeks 1
• Administration: Should be taken with food to increase bioavailability 1
• Efficacy: Single dose provides 62.4% cure rate, increasing to 92.8% with second dose 5
• Limitations:
  • Limited ovicidal activity, requiring second dose after 2 weeks 1
  • Not recommended as first-line for pregnant/lactating women (permethrin preferred) 3
  • Should not be used in children weighing <15 kg (traditional recommendation) 3

Special Populations

Pregnant Women

• First choice: Permethrin 5% cream 3
• Alternative: Ivermectin is classified as "human data suggest low risk" in pregnancy 1
• Avoid: Lindane due to association with neural tube defects 1, 3

Children

• Infants and young children should be treated with permethrin 5% cream 1
• Children under 10 years should not be treated with lindane due to potential neurotoxicity 1, 3
• Permethrin is safe in children 2 months and older 4

Immunocompromised Patients

• Crusted scabies requires combination therapy with topical scabicide and oral ivermectin 6
• More aggressive treatment may be needed with multiple doses of ivermectin 7

Alternative Treatments

Lindane (1%)

• Use only if: Patient cannot tolerate recommended therapies or if these therapies have failed 1
• Contraindications:
  • Extensive dermatitis
  • Children under 10 years
  • Pregnant or breastfeeding women 1
  • Elderly or debilitated persons

Other Options

• Benzyl benzoate 25% lotion 6
• Malathion 0.5% aqueous lotion 6
• Sulphur 6-33% preparations 6

Treatment Approach

Application Technique

• For permethrin: Thoroughly massage into the skin, paying special attention to folds and creases 8
• Consider cold application of permethrin (refrigerated cream) for better efficacy 9
• For severe cases, consider two consecutive daily applications of permethrin (87.2% cure rate vs. 61.8% with single application) 9

Environmental Management

• Decontaminate bedding and clothing by machine washing and drying using hot cycle 1, 3
• Alternatively, remove items from body contact for at least 72 hours 1
• Fumigation of living areas is not necessary 1

Contact Management

• Treat all household members and close contacts simultaneously, even if asymptomatic 3
• Sexual contacts within the previous month should be treated 1
• Avoid sexual contact until patients and partners have been treated 1

Follow-Up and Retreatment

• Evaluate after 1 week if symptoms persist 1
• Retreatment may be necessary if:
  • Mites are still detected
  • No clinical response is achieved with initial regimen 1, 3
• Approximately 75% of patients who still have pruritus at 2 weeks will have resolution by 4 weeks 4

Common Pitfalls to Avoid

1. Inadequate application: Ensure thorough coverage of all skin areas, including folds, creases, and under fingernails
2. Failure to treat contacts: All household members and close contacts must be treated simultaneously
3. Premature bathing: Do not apply permethrin immediately after bathing or showering
4. Inadequate environmental decontamination: Properly wash bedding and clothing
5. Misdiagnosis of persistent symptoms: Post-scabetic itch may persist for weeks after successful treatment
6. Overlooking head involvement: Consider scalp-to-toe application in infants, elderly, or immunocompromised patients 2