What is the treatment for scabies?

From the Guidelines

Scabies is treated primarily with topical permethrin 5% cream as the first-line therapy, applied from neck to toes, including under fingernails, and left on for 8-14 hours before washing off, as recommended by the most recent guidelines 1. The treatment of scabies involves several key steps to ensure effective eradication of the mites and prevention of reinfestation.

• Apply topical permethrin 5% cream from neck to toes, including under fingernails, and leave on for 8-14 hours before washing off, as this has been shown to be effective in treating scabies 1.
• A second application one week later is recommended to kill newly hatched mites, which is crucial in breaking the life cycle of the mite and preventing reinfestation 1.
• Alternative treatments include oral ivermectin (200 mcg/kg, repeated in 7-14 days), especially for widespread or crusted scabies, or topical alternatives like sulfur ointment (5-10%) or benzyl benzoate (10-25%) 1.
• All household members and close contacts should be treated simultaneously, even if asymptomatic, to prevent reinfestation, as recommended by the guidelines 1.
• Clothing, bedding, and towels used in the previous 3 days should be washed in hot water and dried on high heat to decontaminate them, and items that cannot be washed should be removed from body contact for at least 72 hours 1.
• Itching may persist for 2-4 weeks after successful treatment due to hypersensitivity reactions to dead mites, and antihistamines and topical steroids can help manage this itching 1.
• Scabies spreads through prolonged skin-to-skin contact, making it essential to treat all close contacts and household members simultaneously to prevent reinfestation 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. In Scabies: Thoroughly massage into the skin of the whole body, from the chin down, paying particular attention to all folds and creases. The treatment for scabies is:

• Permethrin Cream, 5%: applied from the head to the soles of the feet, left on for 8 to 14 hours, and then washed off. One application is generally curative 2.
• Crotamiton lotion: applied from the chin down, paying attention to folds and creases, with a second application advisable 24 hours later 3.

From the Research

Treatment Options for Scabies

• Local treatments for scabies include synthetic pyrethrins, benzyl benzoate, lindane, and crotamiton 4
• Permethrin 5% cream is considered one of the most effective topical treatments for scabies, with high efficacy and low toxicity 5, 6
• Ivermectin, a systemic antiparasitic agent, has been shown to be effective in treating scabies, particularly in cases of institutional epidemics, profuse scabies, and in HIV-positive patients 4, 7, 8
• Oral ivermectin has been compared to topical treatments such as lindane and permethrin, and has been found to be an effective and cost-comparable alternative 7, 8

Application and Administration

• Permethrin 5% cream should be applied to the entire skin surface, left on for 24 hours, and repeated 7-10 days later 6
• Ivermectin can be administered orally in a single dose of 200 micrograms/kg body weight, with increased compliance and early improvement in signs and symptoms 8
• Topical treatments should be applied properly, including under the fingernails and up to the edge of all body orifices 5

Special Considerations

• Treatment must be adapted case-by-case, according to feasibility, and contacts should be treated to prevent re-infestation 4
• Ivermectin may be particularly useful in cases of keratotic scabies, and should be associated with local treatment 4
• The role of systemic ivermectin in the treatment of scabies remains to be defined, particularly in terms of its relative efficiency over local treatment 4