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 if head involvement is suspected) and leave on for 8-14 hours 1, 2
• A second application is recommended after 1 week to kill newly hatched mites 1
• Permethrin has low mammalian toxicity and minimal allergic side effects, making it safe for most patients 1, 3
• Patients should be advised that temporary exacerbation of itching, mild burning, or stinging may occur after application 4

Alternative Treatments

1. 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 with extensive or crusted scabies
     • Cases where topical treatment is impractical

2. Other alternatives (when permethrin or ivermectin cannot be used):

   • Crotamiton 10% cream/lotion 5, 6
   • Benzyl benzoate 25% lotion 7
   • Malathion 0.5% aqueous lotion 7
   • Sulfur 6-33% preparations 7

Special Populations

• Pregnant and lactating women: Permethrin 5% is preferred due to established safety data 1
• Infants and children:
  • Permethrin 5% is safe and effective in children 2 months and older 4
  • For children under 5 years, some sources recommend using 2.5% permethrin 3
  • Ivermectin should be avoided in children under 15 kg 1
• Immunocompromised patients with crusted scabies require combination therapy with topical scabicide and oral ivermectin 7

Critical Management Steps

1. Treat all household members and close contacts simultaneously, even if asymptomatic 1
2. Decontaminate bedding and clothing:
   • Machine wash with hot water cycle (at least 120°F/49°C)
   • Or keep items out of body contact for at least 72 hours 1
3. Follow-up evaluation after 1 week if symptoms persist 1
4. Inform patients:
   • Pruritus may persist for several weeks after successful treatment 1
   • Approximately 75% of patients who still have itching at 2 weeks will have resolution by 4 weeks 4

Important Considerations and Pitfalls

• Treatment failure causes:

  • Incorrect application technique
  • Insufficient contact time
  • Failure to treat all contacts simultaneously
  • Reinfestation from untreated fomites

• Scalp involvement: While traditionally considered rare in adults, scalp involvement can occur. Consider scalp-to-toes application in cases with head involvement 2

• Comparative efficacy: Studies show that twice application of permethrin with a 1-week interval (92.5% cure rate) is superior to a single dose of ivermectin (85.9% cure rate) 8

• Crusted scabies: Requires more aggressive treatment with combination therapy (topical scabicide plus oral ivermectin) 7

• Screening: Patients should be screened for other sexually transmitted infections as scabies can be sexually transmitted 7