Should scabies be treated with both ivermectin and permethrin (Permethrin)?

From the Guidelines

Scabies should be treated with both ivermectin and permethrin, especially in severe or resistant cases, as this combination therapy has been shown to be effective in treating crusted (Norwegian) scabies and institutional outbreaks. The recommended approach is to use permethrin 5% cream applied to the entire body from the neck down, left on for 8-14 hours, then washed off, with a second application one week later, as stated in the 2015 sexually transmitted diseases treatment guidelines 1. Oral ivermectin is typically given at a dose of 200 mcg/kg body weight, also repeated after 7-14 days, as this has been shown to be effective in killing mites that may be deeper in the skin 1.

Key Considerations

• Permethrin kills the mites and eggs on the skin surface, while ivermectin works systemically to kill mites that may be deeper in the skin 1.
• It's essential to treat close contacts simultaneously, even if they don't have symptoms, and to wash all bedding, clothing, and towels in hot water to prevent reinfestation 1.
• Symptoms may persist for 2-4 weeks after successful treatment due to ongoing immune reactions to dead mites, so antihistamines or topical steroids may help manage itching during this period 1.
• Ivermectin has limited ovicidal activity, and therefore, a second dose should be administered 14 days after the first dose to prevent recurrences from eggs at the time of treatment 1.

Treatment Approach

• For crusted (Norwegian) scabies, combination treatment with a topical scabicide, such as 5% topical permethrin cream, and oral ivermectin 200 ug/kg on days 1,2,8,9, and 15, is recommended 1.
• Additional ivermectin treatment on days 22 and 29 may be required for severe cases 1.
• Lindane should be avoided due to the risks of neurotoxicity with heavy applications or denuded skin 1.

From the Research

Treatment Options for Scabies

• Scabies can be treated with various options, including topical permethrin, systemic ivermectin, and other agents such as crotamiton or benzyl benzoate 2, 3, 4, 5.
• The first line therapy for scabies is typically topical application of permethrin, according to current recommendations 2.
• Systemic ivermectin is also an effective treatment option, and can be used in combination with permethrin for cases that are otherwise intractable, such as crusted scabies 2, 4, 5.

Combination Therapy with Ivermectin and Permethrin

• A combination of permethrin and ivermectin can be used to treat scabies, particularly in cases that are resistant to other treatments or in cases of crusted scabies 2.
• There is evidence to suggest that this combination therapy can be effective in treating scabies, although the exact protocol for combination therapy is not well established 2, 4, 5.
• The use of ivermectin in combination with permethrin may be beneficial in certain cases, such as in institutional outbreaks or in patients with a high prevalence of scabies 4, 5.

Efficacy of Permethrin and Ivermectin

• Permethrin is considered to be a highly effective treatment for scabies, with a high cure rate when used correctly 2, 4, 6.
• Ivermectin is also an effective treatment option, with a high cure rate when used systemically or topically 3, 4, 5.
• The efficacy of permethrin and ivermectin can vary depending on the specific treatment protocol and the individual patient's response to treatment 2, 3, 4, 5, 6.