Repellents are topical products that, when applied to the skin, form a layer of vapor on the skin, with an odor that repels insects, such as repellents that have DEET, icaridin, IR3535 or herbal essential oils in their composition.
In addition to topical repellents, to prevent bites and combat mosquitoes, other measures can also be adopted, especially in closed spaces, such as cooling the house with air conditioning, using mosquito nets, for example.
Topical or environmental repellents help prevent diseases transmitted by mosquitoes, especially mosquitoes. Temples of the Egyptianswhich can cause dengue, Zika or Chikungunya, for example, being able to prevent bites and avoid illnesses
Topical repellents
Some of the most commonly used substances in topical repellents are:
1. DEET
DEET (diethyltoluamide or N,N-diethyl-meta-toluamide) is the most effective repellent currently available on the market, which acts by interfering with the mosquitoes’ antenna, such as Temples of the Egyptians or Anopheles, that transmit diseases such as dengue, Zika, Chikungunya or malaria.
By interfering with the antennae of these mosquitoes, they are repelled as they do not feel the L-lactic acid and carbon dioxide released by the human body, and therefore, do not approach them, causing bites.
Some of the products that have DEET in their composition are:
The higher the concentration of DEET, the longer the repellent’s protection will last.
However, when used in children, a lower DEET concentration should be chosen, less than 10%, which has a shorter duration of action and, therefore, should be applied more frequently, in order to maintain protection. in children over 2 years old.
2. Icaridina
Also known as KBR 3023, icaridin is a repellent derived from pepper that, according to some studies, is 1 to 2 times more effective than DEET against mosquitoes. Temples of the Egyptians.
Some repellent options containing icaridin are:
An advantage of these products is that they have a prolonged action time, up to around 10 hours, in the case of repellents with 20 to 25% concentration of Icaridin.
3. AND 3535
IR 3535 is a synthetic biopesticide that has a good safety profile and is therefore the most recommended for pregnant women, with similar efficacy compared to DEET and icaridin.
This product can also be used in children over 6 months of age, and has a duration of action of up to 4 hours. An example of a repellent with IR3535 is Isdin’s Anti-Mosquito Lotion or Xtream spray.
Read too: How to identify Aedes aegypti (dengue mosquito)
4. Natural oils
Repellents based on natural oils contain herbal essences, such as citrus fruits, citronella, coconut, soy, eucalyptus, cedar, geranium, mint or lemon balm, for example. In general, they are very volatile and, therefore, in most cases they have a short-lasting effect.
Citronella oil is one of the most used, but it is recommended to apply it every hour of exposure.
Furthermore, some studies show that lemon eucalyptus oil, in concentrations of 30%, is comparable to DEET at 20%, providing protection for up to 5 hours, therefore being the most recommended of natural oils and a good alternative for people. who for some reason cannot use DEET or icaridin.
Read too: 8 homemade and natural mosquito repellents
Physical repellents
Non-topical repellents or physical repellents are indicated as auxiliaries to topical repellents or in children under 6 months, who cannot use these products.
Therefore, in these cases, the following measures can be adopted:
- Keep environments refrigerated, as insects prefer warm environments;
- Use simple mosquito nets or those with permethrin on windows and/or around beds and cribs. The pores of mosquito nets should not be larger than 1.5 mm;
- Choose to wear light fabrics and avoid very flashy colors;
- Use natural incense and candles, such as andiroba, remembering that their isolated use may not be enough to protect against mosquito bites and that they only have action when applied for continuous hours and started before the person is exposed to the environment.
These are good options for pregnant women and children under 6 months of age. See other repellents adapted for these cases.
Environmental repellents
Environmental repellents are mainly electrical repellents with tablets or liquids, such as SBP, Raid or electric Exposis, which must be plugged in, releasing the insecticide into the environment, which repels or causes the death of mosquitoes.
In addition to the repellent with tablets or liquid, other options are the blue LED light or the ultrasonic repellent, which are also plugged into the socket and act by attracting mosquitoes, which end up dying when they receive an electric shock.
These electrical devices can complement the protection of topical or physical repellents, and should be kept out of the reach of children.
Repellents with no proven effectiveness
Although they are widely used in clinical practice and some of them are approved by ANVISA, some repellents may not be effective enough to prevent insect bites.
Bracelets soaked in DEET repellents, for example, only protect a small region of the body, up to around 4cm of the area around the bracelet, so it cannot be considered a sufficiently effective method.
Ultrasonic repellers, blue light electrical devices and electrocution instruments have also not been shown to be sufficiently effective in several studies.
How to correctly apply the repellent
To be effective, the topical repellent must be applied as follows:
- Apply the repellent to several areas of the body, trying to avoid distances greater than 4 cm;
- Avoid contact with mucous membranes, such as eyes, mouth or nostrils;
- Reapply the product according to the exposure time, the substance used, the concentration of the product, and the guidelines described on the label.
Repellents should only be applied to exposed areas and, after exposure, the skin should be washed with soap and water, especially before going to sleep, in order to avoid contaminating sheets and bedding, preventing a continuous source of exposure to the sun. product.
In places of high temperature and humidity, the duration of the repellent’s effect is shorter, requiring more frequent reapplications and, in case of activities in water, the product is more easily removed from the skin, therefore, reapplication of the product is recommended. when the person leaves the water.
