What is the recommended treatment for scabies?

Treatment for Scabies

The recommended first-line treatment for scabies is 5% permethrin cream applied to the entire body from neck down for 8-14 hours, with a cure rate of 89-95% at 4 weeks after treatment. 1

First-Line Treatment: Permethrin 5% Cream

Application Instructions:

• Apply 5% permethrin cream to the entire body from the neck down
• Pay special attention to all folds and creases
• Leave on for 8-14 hours (typically overnight)
• Take a cleansing bath 48 hours after application 2
• For infants, young children, and elderly patients with extensive disease, consider scalp-to-toes application as scalp involvement can occur 3

Treatment Schedule:

• A second application is typically recommended after 1 week
• Two applications of permethrin with a 1-week interval has shown superior efficacy (92.5-96.9%) compared to single-dose treatments 4, 5

Special Populations:

• Pregnant or lactating women: Permethrin 5% cream is preferred over oral ivermectin 1
• Infants and children: Safe for use in children 2 months and older 2
• Children under 5 years may use a reduced concentration (2.5%) 6

Alternative Treatment: Oral Ivermectin

• Dosage: 200 μg/kg, repeated in 2 weeks
• Should be taken with food to increase bioavailability 1
• Single-dose efficacy: 62.4-85.9%, increasing to 92.8-100% with a second dose 4, 5
• Consider for patients who cannot tolerate topical treatments or have treatment failures
• Not recommended as first-line therapy due to:
  • Lower efficacy with single dosing compared to permethrin
  • Limited ovicidal activity requiring repeat dosing
  • Less established safety data in breastfeeding women 1

Additional Management Steps

Environmental Measures:

• Decontaminate bedding and clothing by:
  • Machine washing and drying using hot cycle
  • OR removing items from body contact for at least 72 hours 1
• Change clothing and bed linen the day after treatment 2, 7

Treatment of Contacts:

• Treat all household members and close contacts simultaneously, even if asymptomatic
• Include sexual contacts from the previous month 1

Follow-up:

• Evaluate after 1 week if symptoms persist
• Retreatment may be necessary if:
  • Mites are still detected
  • No clinical improvement is observed 1
• Note that pruritus may persist for up to 4 weeks after successful treatment (75% of patients with persistent pruritus at 2 weeks had resolution by 4 weeks) 2

Common Pitfalls and Caveats

1. Inadequate application: Ensure thorough coverage of all skin areas, especially folds and creases
2. Failure to treat contacts: All household members must be treated simultaneously to prevent reinfection
3. Premature treatment cessation: Patients may stop treatment when itching improves, but complete the full course
4. Misinterpreting persistent pruritus: Itching may continue for weeks after successful treatment and doesn't necessarily indicate treatment failure
5. Neglecting environmental decontamination: Bedding and clothing must be properly cleaned to prevent reinfestation
6. Inadequate nail care: Trim fingernails short and apply medication under nails as parasites can hide there 7

Permethrin has low mammalian toxicity and minimal allergic side effects compared to alternatives like lindane, which should be avoided due to potential neurotoxicity, especially in children under 10 years and pregnant women 1, 6.

Human scabies is highly contagious, and proper treatment of the patient and all contacts is essential for preventing spread and recurrence of infestation.