What are the treatment options for scabies?

From the Guidelines

Scabies treatment should prioritize a combination of oral ivermectin and topical permethrin for crusted scabies, while permethrin 5% cream is the first-line treatment for typical scabies. The treatment of scabies, particularly crusted scabies, requires a comprehensive approach to ensure effective management and prevention of reinfestation 1.

Treatment Options

• Permethrin 5% cream applied from neck to toes, left on for 8-14 hours, then washed off, with a second application one week later, is considered the first-line treatment for typical scabies.
• Alternatives include ivermectin pills (200 mcg/kg, repeated in 1-2 weeks), benzyl benzoate 25% lotion, or crotamiton 10% cream.
• For crusted (Norwegian) scabies, a combination of oral ivermectin and topical permethrin is often needed, with oral ivermectin 200 ug/kg on days 1,2,8,9, and 15, and additional treatment on days 22 and 29 for severe cases 1.

Management Considerations

• All household members and close contacts should be treated simultaneously, even if asymptomatic, to prevent reinfestation 1.
• Bedding, clothing, and towels should be washed in hot water and dried on high heat to prevent fomite transmission.
• Itching may persist for 2-4 weeks after successful treatment due to ongoing immune response to dead mites and their waste, and can be managed with antihistamines or topical steroids 1.
• Retreatment 2 weeks after the initial treatment regimen can be considered for those persons who are still symptomatic or when live mites are observed, with an alternative regimen recommended for those who do not respond initially to the recommended treatment 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Adults and children Thoroughly massage Permethrin Cream, 5% into the skin from the head to the soles of the feet. Scabies rarely infests the scalp of adults, although the hairline, neck, temple, and forehead may be infested in infants and geriatric patients. Usually 30 grams is sufficient for an average adult. The cream should be removed by washing (shower or bath) after 8 to 14 hours. Infants should be treated on the scalp, temple, and forehead. ONE APPLICATION IS GENERALLY CURATIVE. Patients may experience persistent pruritus after treatment. This is rarely a sign of treatment failure and is not an indication for retreatment. Demonstrable living mites after 14 days indicate that retreatment is necessary.

The treatment option for scabies is Permethrin Cream, 5%. The recommended application is a single treatment, where the cream is massaged into the skin from the head to the soles of the feet, and then removed after 8 to 14 hours. Key points include:

• One application is generally curative 2
• Retreatment is necessary if demonstrable living mites are present after 14 days 2
• Persistent pruritus after treatment is not usually a sign of treatment failure 2

From the Research

Treatment Options for Scabies

• Topical permethrin 5% cream is considered an effective treatment for scabies, with a study showing that applying it once daily for two consecutive days is more effective than a single application 3.
• The application of permethrin 5% cream from neck down is the current guideline, but there are cases where scalp-to-toes application is necessary, especially in infants and older adults with scalp involvement 4.
• Other treatment options include allethrin and ivermectin, with ivermectin being particularly useful in treating crusted scabies 5.
• Oral ivermectin has been shown to be safe, easier to use, and more effective than topicals in widespread institutional scabies, and is considered the treatment of choice in large populations and for crusted scabies 6.

Comparison of Treatment Options

• A study comparing topical permethrin and oral ivermectin found that oral ivermectin may lead to slightly lower rates of complete clearance after one week, but there may be little or no difference after two weeks 7.
• The study also found that there is probably little or no difference in rates of complete clearance between systemic ivermectin and topical ivermectin, and between ivermectin lotion and permethrin cream 7.
• The safety of permethrin and ivermectin was also compared, with no withdrawals due to adverse events occurring in either group, and few and mild adverse events reported 7.

Application and Dosage

• Permethrin 5% cream should be applied to the entire skin surface, left on for 24 hours, and repeated 7-10 days later 3.
• Oral ivermectin should be taken in a single dose of 200 µg/kg, with food, and repeated in 10-14 days to enhance effectiveness 6.
• The treatment dose for non-crusted scabies is 200 µg/kg, and for crusted scabies, a single dose of ivermectin can be repeated on day 8 if necessary 5, 6.