From the Guidelines
Yes, a patient can be treated again with permethrin cream for persistent scabies symptoms, and retreatment can be considered 2 weeks after the initial treatment regimen if live mites are observed or symptoms persist 1. If itching continues after two treatments, a third application of permethrin 5% cream can be considered. The standard regimen is to apply permethrin cream from neck to toes, leave on for 8-14 hours (usually overnight), then wash off, as recommended by the guidelines 1. For persistent cases, some clinicians recommend two consecutive nights of application followed by a repeat treatment one week later. Key considerations include:
- Ensuring the patient is applying the cream properly to the entire body (including under fingernails, between toes, and all skin folds)
- Treating all household members simultaneously
- Decontaminating bedding and clothing Persistent symptoms may indicate treatment failure due to incorrect application, reinfestation from untreated contacts, or rarely, resistance to permethrin. If symptoms persist after a third treatment, alternative medications like ivermectin might be necessary, and the patient should be reevaluated to confirm the diagnosis or identify other causes of itching, as post-scabetic itch can persist for weeks after successful treatment due to hypersensitivity reactions to dead mites.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Adults and children ... 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 patient can be treated again with permethrin cream if there are demonstrable living mites after 14 days.
- The patient should wait at least 14 days after the first two treatments to determine if retreatment is necessary. 2
From the Research
Treatment of Scabies with Permethrin Cream
- The patient has already been treated twice with permethrin cream for scabies, but the itching continues 3, 4, 5, 6.
- According to the studies, treatment with permethrin cream can be repeated if there is treatment failure at the 2-week follow-up 3.
- The recommended interval between treatments is 1-2 weeks 3, 4, 5, 6.
- It is essential to note that the efficacy of permethrin cream increases with repeated applications 3, 4, 5, 6.
- For example, a study found that two applications of permethrin 2.5% cream with a 1-week interval between them was effective in 65.8% of patients at the 2-week follow-up, which increased to 89.5% at the 4-week follow-up after this treatment was repeated 3.
- Another study found that two applications of permethrin with a one week interval was effective in 96.9% of patients 5.
Waiting Period After First Two Treatments
- The waiting period after the first two treatments can be 1-2 weeks before repeating the treatment 3, 4, 5, 6.
- A study found that repeating the treatment 7-10 days later was effective in treating scabies 7.
- It is crucial to evaluate the treatment at intervals of 2 and 4 weeks to determine the need for repeated treatment 3, 4, 5, 6.