Mosquito repellents work by making us less attractive to mosquitoes. They work by repelling insects, not killing them. There are a number of options available to consider. Read more...
Topics
Which types of bugs do insect repellents repel?
Let's talk insect repellent options. What is available and how do they work?
Are there any foods or drinks in our diet that make us more attractive to mosquitoes?
Are insect repellents safe to use for children?Are insect repellents safe to use while pregnant?
Where does insect repellent fit in the steps of my skincare routine?
Photo: Wix
Disclaimer: This page contains affiliate links to products. We may receive a commission for purchases made through these links.
Why do we need mosquito repellents?
Repelling insects is not just about the nuisance factor of having them fly or buzz around us when we are trying to enjoy our time outdoors. Some insects can play a role in transmitting disease. These diseases are referred to as vector-borne illnesses. These illnesses are first acquired when insects that take a blood meal to complete their cycle of laying eggs feed on an infected person or mammal. They then acquire the parasite or virus from the infected individual and then land on another unsuspecting animal or human, taking another blood meal while transmitting the disease acquired.
The most common diseases that tend to be targeted by insect repellents are Malaria, Zika virus, West Nile virus, Dengue fever, and Lyme disease.
Video: Techei
Which types of bugs do insect repellents repel?
The use of insect repellents is primarily to prevent insects from biting our skin given the risk of transmitting disease. In fact, the earliest insect repellents, such as DEET, were formulated for the US military to protect military personnel from vector-borne illnesses such as malaria, yellow fever, and dengue.
The primary focus of most repellents from a development perspective was the Aedes aegypti mosquito and the Anopheles mosquito. This particular Aedes species is a known vector of chikungunya, yellow fever, dengue, and Zika virus. The Anopheles is a known vector for a parasite of the Plasmodium genus that can cause malaria.
It has been noted that insect repellents can work against mosquitoes, fleas, ticks, biting flies, and chiggers depending on the concentration.
What makes it challenging for consumers to understand insect repellents is assigning the broad name "insect" to a product that was technically designed to address mosquito-borne illness. We have expanded the concept in recent years given the need to address ticks and other hematophagous bugs (blood-feeding) but the research was specifically focused on mosquitos. The repellents themselves are focused on the olfactory receptors in mosquitos.
How do insect repellents work?
So it’s true there are people that are just more attractive to mosquitoes than others. I’ve always considered myself a "mosquito magnet" wherever I go. Research seems to suggest that there are a number of factors that can attract these insects that draw them in such as carbon dioxide that is exhaled, body heat, carboxylic acids in our skin, and skin odor. Although some reports have attempted to link blood type (ABO) to the tendency to be bitten, there is little data to support this.
Insect repellents generally work by deterring insects from our skin based on recognizing the scents that they favor and dislike to make them less like to land and bite.
Let's talk insect repellent options. What is available and how do they work?
Insect repellents come in lots of different varieties and forms. It's important to know how each works to find your best option based on intent- is your goal to prevent vector-borne illness or just to get rid of some flying critters in your outdoor space because you find them annoying? You will find topical lotions and sprays for your skin, sprays for your clothing, sprays for your yard, electronic devices, candles, torches, zappers, wearable bands, and more. If I do not cover something, drop me a message and I will update the article!
Starting with topicals for your skin, what are the ingredients available, how are they used, and are there any risks to using them?
The following ingredients are registered with the Environmental Protection Agency (EPA) as safe and effective when used as directed according to the CDC.
Synthetic
DEET
Picaridin (known as KBR 3023 and icaridin outside the US)
IR3535
Natural
Oil of lemon eucalyptus (OLE) (or synthetic version Para-menthane-diol (PMD))
Citronella
2-undecanone
Ingredient | How it works | Targets | Duration of Action | Risks |
DEET | Interacts with Odorant Receptors on Mosquitos to divert them away | MosquitoesBiting fliesGnatsChiggersTicks | ||
Picaridin | Stimulates sensory receptors on Mosquito antennae to make the mosquito not able to detect its host. | Well tolerated Does not tend to damage fabrics | ||
IR3535 | ||||
Oil of lemon eucalyptus (OLE) P-menthane-3,8-diol (PMD) (extract from lemon eucalyptus, Corymbia citriodora) | Unclear mechanism of action Unstable in air and high temperature | 10% to 40% : comparable to low concentrations of DEET | | |
Citronella (extracted from Cymbopogon nardus) | Unclear mechanism of action | Eye irritation Contact dermatitis | ||
Catnip Oil (nepetalactone) Nepeta cataria | Not Known | Mosquitos Black Flies | 7-15% 7 hours | |
2-undecanone (methyl nonyl ketone) extracted from wild tomato (Lycopersicon hirsutum Dunal f. glabratum C. H. Müll) | Not Known | Mosquito | Unclear data on efficacy and duration | |
Please note hyperlinks link to references for data in the literature.
Are there any foods or drinks in our diet that make us more attractive to mosquitoes?
There is not a lot of research on this topic, however, there are some studies linking some items to making us more attractive to mosquitoes. The food and drink items with hyperlinked studies are below for reference.
Are insect repellents safe to use for children?
Remember that the point of wearing an insect repellent is not just to avoid the nuisance of bites- it is actually to reduce the transmission of illness, some of which can be severe, the benefits of wearing insect repellent outweigh the risks.
As a mom and a Dermatologist, I look at this through the lens of needing an effective product while understanding how these products work and best practices help reduce unnecessary exposure.
Let's review DEET use in children first. DEET gained attention for possible risks associated with absorption leading to possible encephalopathy. There is a study that sought to study if it was the concentration of the DEET in these products or if it was the fact that the product is applied to the skin directly that leads to toxicity. This study found that regardless of strength and duration of exposure the potential for toxicity still exists. It is known that absorption of DEET through the skin can occur and of course, with a smaller body surface area for children, the risk of absorption can be higher. Concentrations of DEET in different formulations vary. Higher concentrations do not protect more, they just allow for a longer duration of action. With all this being said, in the past with fewer options in certain circumstances, it may have been important to still consider use but we have other options now available for consideration. Of note, the American Academy of Pediatrics recommends that the maximum concentration of DEET should not exceed 30% and should not be used in children under the age of 2.
My recommendation for my patients and my own family tends to be the use of Picaridin based on safety and effectiveness.
Are insect repellents safe to use while pregnant?
Pregnancy presents a special challenge for vector-borne illness. Pregnant women are thought to be twice as attractive to mosquitoes compared to the nonpregnant state.
The EPA has determined that the use of DEET during pregnancy is safe and the FDA has considered the use of DEET during pregnancy safe during 2nd and 3rd trimesters.
Again, I tend to recommend Picaridin with its strong safety profile and minimal absorption for routine use. However, for travel in high-risk regions, I would stick with DEET as your active.
Where does insect repellent fit in the steps of my skincare routine?
Ideally, an insect repellent is applied after the application of your sunscreen. If sunscreen needs to be reapplied, it is unclear how much effectiveness your insect repellent will retain. Also, note that DEET has been shown to be absorbed into the bloodstream. Chemical sunscreens are also absorbed into the bloodstream. When chemical sunscreens are applied with DEET, both the DEET and chemical sunscreen additives will INCREASE absorption!
Given this fact, I recommend the use of Picaridin if using chemical sunscreen products as this ingredient has actually been shown to DECREASE the absorption of chemical sunscreens giving it another added advantage.
Does sunscreen interact with insect repellents?
Since sunscreen is applied first and insect repellent after, there are studies evaluating how the two may interact. It turns out that DEET is absorbed into the bloodstream as are chemical sunscreens. When the two are applied together, DEET will accelerate the absorption of chemical sunscreen ingredients as well as DEET itself. To avoid compounding toxicity, DEET and chemical sunscreen ingredients should not be used together. Ideally if using DEET as your active ingredient for insect repellent, it is best to use mineral sunscreens to avoid this risk.
An interesting factoid is that the use of Picaridin as your insect repellent after the application of chemical sunscreens will actually decrease your absorption of chemical sunscreen additives. Picaridin itself shows minimal evidence of absorption. So if you prefer to use chemical sunscreen products, stick with Picaridin as your insect repellent of choice when possible to enhance safety.
Are there other means of protecting from insects that do not require the use of a repellent on our skin?
Physical means of preventing insect bites are extremely important to integrate into day-to-day living to reduce the chances of contact.
Long sleeve clothing
Some research historically suggests white or light colors are less attractive to mosquitos
Permethrin-sprayed clothing (can provide between 70 to 90% protection)
Decreasing vegetation buildup and pools of standing water in outdoor spaces
Mosquito nets
Stay indoors
Environmental intervention tactics include:
Adding fish to water reserves that consume mosquito larvae such as Gambusia affinis
Adding nonpathogenic bacteria to the water supply such as Bacillus thuringiensis
Genetically modifying male mosquitos to pass a bacteria on called Wolbachia that can induce infertility in female mosquitos
Comentarios