What is the recommended treatment for Sarcoptosis (scabies)?

Recommended Treatment for Scabies (Sarcoptosis)

Permethrin 5% cream is the first-line treatment for scabies, with a cure rate of 89-95% at 4 weeks after treatment. 1 This medication is FDA-approved specifically for the treatment of Sarcoptes scabiei infestation (scabies). 2

First-Line Treatment: Permethrin 5% Cream

• Apply from neck down to the entire body
• Leave on for 8-14 hours before washing off
• Requires a second application 7-10 days later to kill newly hatched mites 1, 3
• Cold application of permethrin (refrigerated cream) may increase efficacy 3
• For better results, consider applying once daily for two consecutive days, which has shown superior efficacy (87.2% vs 61.8% cure rate) compared to single application 3

Alternative Treatments

1. Oral Ivermectin

   • Dosage: 200 μg/kg body weight
   • Repeat dose after 14 days
   • Take with food to increase bioavailability
   • Particularly useful for:
     • Crusted scabies
     • Immunocompromised patients
     • Outbreaks in institutional settings
     • Cases where topical treatments have failed 1, 4

2. Crotamiton

   • FDA-approved for scabies treatment 5
   • Also provides symptomatic relief for pruritus
   • Less effective than permethrin or ivermectin

3. Topical Ivermectin 1%

   • Applied to affected skin at 400 μg/kg
   • Repeated after one week
   • Comparable efficacy to permethrin (84.2% vs 89.5% cure rate at 4 weeks) 6

Special Populations

Pregnancy and Lactation

• Permethrin 5% is preferred due to established safety data 1
• Avoid lindane due to association with neural tube defects

Children

• Permethrin 5% is first choice for all ages including infants
• Ivermectin should be avoided in children under 15 kg
• Never use lindane in children under 10 years due to neurotoxicity risk 1

Management of Secondary Bacterial Infections

• For impetiginized scabies (secondary bacterial infection):
  • Combination of permethrin 5% with fusidic acid 2% cream is more effective than permethrin alone
  • Staphylococcus aureus is the most common causative organism 7

Critical Prevention Measures

• Simultaneously treat all household members and close contacts, even if asymptomatic
• 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

Follow-Up and Treatment Failure

• Evaluate after 1 week if symptoms persist
• Repeat treatment if:
  • Mites are still detected
  • No clinical improvement is observed
• Note: Pruritus may persist for several weeks after successful treatment 1

Common Pitfalls to Avoid

1. Failure to treat contacts - most common cause of treatment failure and reinfestation
2. Inadequate application - ensure complete coverage from neck down
3. Not repeating treatment - single application is insufficient due to mite life cycle
4. Ignoring persistent symptoms - post-scabetic itch can last weeks and doesn't indicate treatment failure
5. Overdiagnosis of treatment failure - distinguish between persistent mites vs post-scabetic dermatitis

Treatment Comparison

Permethrin is superior to single-dose ivermectin (92.5% vs 85.9% cure rate), though both reach high efficacy when properly administered with follow-up treatments 8. Permethrin also provides faster symptomatic relief.