What is the recommended treatment for scabies?

Recommended Treatment for Scabies

The first-line treatment for scabies is 5% permethrin cream applied to the entire body from neck down for 8-14 hours, with a single application generally being curative. 1, 2

Primary Treatment Approach

• 5% Permethrin Cream (First-line):
  • Apply thoroughly from head to soles of feet (scalp treatment typically only needed for infants and elderly)
  • Leave on for 8-14 hours then wash off
  • Usually 30 grams is sufficient for an average adult 2
  • Cure rate of 89-95% at 4 weeks after treatment 1

Application Instructions

1. Thoroughly massage the cream into all skin surfaces
2. For adults, scalp is rarely infested (except hairline, neck, temple, and forehead)
3. For infants and geriatric patients, include treatment of scalp, temple, and forehead 2
4. Remove by washing (shower or bath) after 8-14 hours

Important Considerations

• Treat all household members and close contacts simultaneously, even if asymptomatic, to prevent reinfection 1
• Sexual contacts within the previous month should also be treated 1
• Decontaminate bedding and clothing by machine washing and drying using hot cycle, or remove items from body contact for at least 72 hours 1
• Persistent pruritus after treatment is common and rarely indicates treatment failure (symptoms may persist for 2-6 weeks after successful treatment) 2, 3

Alternative Treatment

• Oral ivermectin:
  • Dosage: 200 μg/kg
  • Should be repeated in 2 weeks due to limited ovicidal activity 1
  • Take with food to increase bioavailability 1
  • Single dose provides cure rate of 62.4%, increasing to 92.8% with second dose 4
  • Not first-line for pregnant or breastfeeding women 1

Special Populations

• Pregnant or lactating women: Permethrin 5% cream is preferred over oral ivermectin 1
• Infants and young children: Use permethrin 5% cream 1
• Immunocompromised patients: May develop crusted scabies requiring combination therapy with topical scabicide and oral ivermectin 5

Follow-up and Retreatment

• Evaluate after 1 week if symptoms persist
• Retreatment is necessary only if living mites are detected after 14 days 1, 2
• Follow-up examinations should be performed to verify eradication 1

Common Pitfalls and Caveats

• Failure to treat all contacts simultaneously is a common cause of treatment failure and reinfection 3
• Mistaking post-treatment pruritus for treatment failure - itching commonly persists for 2-6 weeks after successful treatment 3
• Inadequate application - ensure complete coverage of all skin surfaces
• Secondary bacterial infections - Staphylococcus aureus is the most common cause and may require additional treatment 6

Treatment Efficacy Comparison

Recent evidence suggests that two applications of permethrin with a one-week interval (96.9% effective) is more effective than a single dose of ivermectin (62.4% effective), though two doses of ivermectin approaches the efficacy of permethrin 4. However, the FDA label indicates that one application of permethrin is generally curative 2, making it the most straightforward first-line option.