What is the diagnosis and treatment for scabies (sarcoptic mange)?

From the Guidelines

Scabies treatment should involve applying permethrin 5% cream from neck to toes, leaving it on for 8-14 hours, then washing it off, and repeating the application after 7 days, as this approach has been shown to be effective in managing the condition 1. When it comes to scabies, particularly crusted scabies, the treatment approach may need to be more aggressive, involving a combination of topical scabicide, such as 5% topical permethrin cream, and oral ivermectin treatment 1.

• The application of permethrin 5% cream should be done from neck to toes, left on for 8-14 hours, and then washed off, with the application repeated after 7 days.
• For severe cases, such as crusted scabies, oral ivermectin may be prescribed at 200 mcg/kg, with a second dose given 1-2 weeks later, and additional doses on days 22 and 29 may be required for severe cases 1.
• All household members and close contacts should be treated simultaneously, even if they don't show symptoms, to prevent reinfection.
• Bedding, clothing, and towels used within 3 days before treatment should be washed in hot water and dried on high heat to decontaminate them, as recommended by the guidelines 1.
• Intense itching may persist for 2-4 weeks after successful treatment due to the body's allergic response to the dead mites, and over-the-counter antihistamines and prescribed corticosteroid creams can help manage this itching.
• It's also important to note that scabies spreads through prolonged skin-to-skin contact, making it common in households, childcare settings, and nursing homes, and that the mites burrow into the skin, causing the characteristic itching that typically worsens at night.
• In cases where symptoms persist or worsen after treatment, retreatment 2 weeks after the initial treatment regimen can be considered, and the use of an alternative regimen is recommended for those persons who do not respond initially to the recommended treatment 1.

From the FDA Drug Label

Permethrin Cream, 5% is indicated for the treatment of infestation with Sarcoptes scabiei (scabies). Adults and children Thoroughly massage Permethrin Cream, 5% into the skin from the head to the soles of the feet. ONE APPLICATION IS GENERALLY CURATIVE. For eradication of scabies ( Sarcoptes scabiei) and for symptomatic treatment of pruritic skin.

Scabies Treatment: Permethrin cream 5% is indicated for the treatment of scabies infestation.

• The treatment involves thoroughly massaging the cream into the skin from the head to the soles of the feet.
• One application is generally curative 2, 2.
• Another option for scabies treatment is crotamiton, which is used for eradication of scabies and symptomatic treatment of pruritic skin 3.

From the Research

Causes and Treatment of Scabies

• Scabies is a contagious skin infection caused by the human itch mite (Sarcoptes scabiei va. hominis) 4.
• The treatment of scabies is still controversial, with various options available, including topical insecticides such as permethrin and ivermectin 4, 5.

Efficacy of Different Treatments

• Topical permethrin is considered the most effective treatment for classic scabies, with a strength of recommendation of A, based on meta-analyses with consistent results 5.
• Ivermectin, both topical and oral, has been shown to be effective in treating scabies, although its efficacy may vary depending on the population and the specific treatment regimen 4, 5, 6.
• Crotamiton cream has been found to be less effective than permethrin and ivermectin in treating scabies, with cure rates ranging from 41.2% to 65% 6, 7, 8.

Comparison of Treatments

• A study comparing permethrin 5% cream with crotamiton 10% cream found that permethrin was significantly more effective, with a cure rate of 81.3% compared to 53.8% for crotamiton 7.
• Another study comparing topical ivermectin with crotamiton 10% cream found that ivermectin was more effective, with a cure rate of 64.7% at the 2-week follow-up, increasing to 82.3% at the 4-week follow-up after repeating the treatment 6.
• A study comparing permethrin 5% cream with crotamiton 10% cream found that permethrin was more effective, with a cure rate of 70% at the 2-week follow-up, increasing to 85% at the 4-week follow-up after repeating the treatment 8.