Study summary
Repellent efficacy of DEET, Icaridin, and EBAAP against Ixodes ricinus and Ixodes scapularis nymphs (Acari, Ixodidae)
Büchel K, Bendin J, Gharbi A, Rahlenbeck S, Dautel H
Read the original paper- Study type
- Lab
- Year
- 2015
- Sample size
- 10 subjects
- Species tested
- Ixodes ricinus, Ixodes scapularis (nymphs)
- Published in
- Ticks and Tick-borne Diseases
- Evidence strength
- Well-supported evidence
How it was tested
Ethanolic solutions were applied to the forearms of 10 volunteers under the EPA product-performance protocol, with tick nymphs repeatedly placed below the treated zone until protection failed, out to 12.5 hours.
Summary
A human-skin study testing whether two lower-strength alternatives, 10% picaridin (icaridin) and 10% IR3535 (EBAAP), can match 20% DEET at repelling the two most important Ixodes tick species. Picaridin came out on top.
Key findings
10% picaridin gave the longest protection, a median 8 hours against the European Ixodes ricinus and 5 hours against the blacklegged Ixodes scapularis, beating 20% DEET (about 4 to 4.5 hours) at half the concentration. 10% IR3535 was roughly on par with DEET at 3.5 to 4 hours. So the ranking was picaridin ahead of DEET, with IR3535 close behind, and picaridin's edge was largest against the European tick.
Limitations
Only 10 volunteers, and the actives were plain ethanol solutions rather than finished consumer products, so real formulations may differ; only nymphs of two species were tested.