From the Guidelines
The recommended prescribed topical skin repellents include DEET (N,N-diethyl-meta-toluamide), picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthane-diol (PMD), and 2-undecanone, as stated in the 2021 guidelines by the Infectious Diseases Society of America (IDSA) 1.
These repellents are effective against mosquitoes, ticks, flies, and other biting insects that can transmit diseases.
- DEET is considered the gold standard and is available in concentrations from 5% to 100%, with higher concentrations providing longer protection (up to 12 hours for 30-50% DEET).
- Picaridin is equally effective as DEET and less irritating, available in 5-20% concentrations providing 4-8 hours of protection.
- IR3535 offers 4-8 hours of protection at 20% concentration.
- OLE and PMD provide up to 6 hours of protection and are plant-based alternatives.
For application,
- cover all exposed skin,
- avoid eyes, mouth, and wounds,
- and reapply as directed on the product label or after swimming/sweating. Children should use concentrations of 30% or less, and repellents should not be used on infants under 2 months old. These repellents work by creating a vapor barrier that interferes with insects' ability to detect human scent or by directly repelling them through their odor.
It's worth noting that other studies, such as those on acne management 1, and other skin conditions 1, do not provide relevant information on prescribed topical skin repellents. Therefore, the recommendation is based solely on the guidelines provided by the IDSA 1.
From the Research
Prescribed Topical Skin Repellents
- The most commonly used active ingredients in topical insect repellents are N,N-diethyl-meta-toluamide (DEET) and picaridin 2, 3.
- DEET is the oldest and most powerful repellent available, but it can be toxic, especially for children under 6 months and pregnant women 3, 4.
- Picaridin is as potent as DEET but less toxic, and it has the advantage of long-lasting action 2, 3.
- IR3535 (Ethyl Butylacetylaminopropionate) is another option that is less toxic than DEET and can be prescribed for children over 6 months and pregnant women 3, 5.
- Oil of lemon eucalyptus (p-menthane-3,8-diol or PMD) is also a topical insect repellent that can offer better protection than DEET alone in certain cases 5.
Recommended Repellents
- For adults, DEET, picaridin, and IR3535 are recommended 3, 5.
- For children over 6 months and pregnant women, IR3535 and picaridin are recommended due to their lower toxicity levels 3, 5.
- For children under 6 months, it is recommended to consult a doctor before using any insect repellent 3.
Formulations
- Topical insect repellents can be formulated as sprays, lotions, creams, or gels 3.
- Controlled release systems (CRS) can be used to increase the duration of repellent action and reduce skin permeation and systemic toxicity 3.
- New formulations are being developed to improve the efficacy and safety of topical insect repellents 3, 6.