In the development of Skabi-Rid, a single-centre, randomised, investigator-blind, parallel-group study compared the safety and efficacy of one application of permethrin 5% lotion with two applications of benzyl benzoate 25% emulsion in the treatment of scabies. The study was performed by SACT (South African Clinical Trials), led by Prof. Otto Müller.
Results
| Permethrin 5% lotion (one application) | Benzyl benzoate 25% (two applications) | |
|---|---|---|
| Cure rate on day 29 | 70.7% | 67.8% |
| No remaining skin lesions on day 29 | 86.2% | 76.3% |
Both treatments were well tolerated. Most adverse events were mild and considered unrelated to the products. The most common treatment-related effect was a transient burning sensation soon after the first application, a known side effect of benzyl benzoate and, to a lesser extent, permethrin. No significant changes were seen in laboratory tests.
Conclusion of the study: permethrin 5% lotion and benzyl benzoate 25% emulsion showed similar efficacy. Permethrin 5% offers an advantage for completing treatment because of its safety profile and the fact that it needs just a single application. The outcome supports the South African Standard Treatment Guidelines recommendation of permethrin 5% as first-line treatment for scabies.
Study design
Primary objective
To evaluate the efficacy of a single application of permethrin 5% lotion compared with benzyl benzoate 25% emulsion applied as two separate applications 12 hours apart, measured by treatment response on day 29 or at early discontinuation.
Secondary objectives
- Safety and tolerability, from reported and observed adverse events and clinical laboratory values.
- Treatment response on day 15.
- Change in itch severity from baseline to day 29 on a modified pruritus score.
- Change in severity of infestation from baseline to day 29 on a 5-point scale.
Participants
120 volunteers (36.7% male, 63.3% female) with signs compatible with scabies: mites, eggs, larvae or droppings seen on skin scrapings, or at least three of these clinical criteria: a burrow, scabies lesions at the classic sites, itching at night, and a family history of similar illness. To prevent re-infection, infected household members were invited to take part or agreed to be treated with benzyl benzoate 25% emulsion.
Treatments
- Treatment A: benzyl benzoate 25% emulsion (Ascabiol, Pharmacare), two applications 12 ± 2 hours apart.
- Treatment B: permethrin 5% lotion (TomarMed, batch TT031), one application, followed by a matching placebo lotion 12 ± 2 hours later to keep the investigator blind.
Definition of cure
No itch, no skin lesions and no mites or their products on microscopy.
S0 Skabi-Rid is a registered medicine (Reg. No. A40/13.2/0756). Read the package insert before use. If symptoms persist, see your doctor or pharmacist.