What is the recommended treatment for scabies?

Treatment of Scabies

Permethrin 5% cream is the recommended first-line treatment for scabies, with a cure rate of 89-95% at 4 weeks after treatment. 1

First-Line Treatment: Permethrin 5% Cream

• Apply permethrin 5% cream from neck down (or scalp-to-toes in cases with head involvement) 2
• Leave on for 8-14 hours before washing off 1
• A second application 24 hours later is advisable to ensure complete eradication 1
• Permethrin has low mammalian toxicity and minimal allergic side effects 1, 3
• Adverse effects are typically limited to mild local reactions such as temporary exacerbation of pruritus, mild burning, or stinging 4

Application Instructions

1. Take a bath or shower before application
2. Thoroughly massage the cream into the skin from chin down (or including scalp if needed)
3. Pay special attention to skin folds, creases, and under fingernails
4. Leave on for 8-14 hours (typically overnight)
5. Wash off with a cleansing bath 48 hours after the last application

Alternative Treatments

Oral Ivermectin

• Dosage: 200 μg/kg, repeated after 14 days 1
• Take with food to increase bioavailability 1
• Particularly useful for:
  • Treatment failures with permethrin
  • Patients unable to apply topical treatments
  • Crusted (Norwegian) scabies (combined with topical treatment)
  • Mass treatment in endemic settings 5

Other Alternatives

• Benzyl benzoate 25% lotion 5
• Crotamiton 10% cream - less effective than permethrin (60% vs 89% cure rate at 4 weeks) 6
• Malathion 0.5% aqueous lotion 5
• Sulfur 6-33% preparations 5

Special Populations

Pregnancy and Lactation

• Permethrin 5% cream is preferred due to established safety data 1
• Animal studies show no evidence of impaired fertility or harm to the fetus 4
• Consider temporarily discontinuing breastfeeding during treatment due to potential excretion in breast milk 4

Children

• Permethrin 5% cream is safe and effective in children 2 months and older 4
• For infants under 2 months, safety has not been established 4
• Avoid lindane in children under 10 years due to potential neurotoxicity 1

Elderly

• Standard treatment with permethrin is appropriate 4
• No dosage adjustment needed for renal impairment as topical permethrin is metabolized in the liver and excreted as inactive metabolites 4

Comprehensive Management

Prevention of Reinfestation

• Simultaneously treat all household members and close contacts, even if asymptomatic 1
• Machine wash bedding and clothing in hot water cycle or keep out of body contact for at least 72 hours 1
• Change clothing and bed linen the day after treatment 7

Follow-up

• Pruritus may persist for several weeks after successful treatment 1
• Approximately 75% of patients with persistent pruritus at 2 weeks will have resolution by 4 weeks 4
• Evaluate after 1 week if symptoms persist 1
• Consider repeat treatment if mites are detected or there is no clinical improvement 1

Partner Management

• Look-back period of 2 months for sexual contacts 5
• Screen for other sexually transmitted infections 5
• Avoid sexual contact until completion of treatment 5

Clinical Pearls and Pitfalls

• Common pitfall: Failure to treat all close contacts simultaneously, leading to reinfestation
• Important caveat: Consider scalp-to-toes application in infants and some adults, as head involvement can occur 2
• Treatment failure causes: Incorrect application, inadequate contact time, or reinfestation from untreated contacts
• Diagnostic challenge: Persistent pruritus after treatment does not necessarily indicate treatment failure, as it may take up to 4 weeks to resolve 4
• Crusted scabies: Requires combination therapy with both topical scabicides and oral ivermectin 5