Insect-borne diseases affect millions of people worldwide, causing diseases in more than 700 million people a year, mainly in tropical countries, so it is very important to focus on prevention, and the use of repellents is an excellent solution to prevent bites and prevent disease.
Topical repellants can be synthetic or natural, which act by forming a layer of vapor on the skin, with an odor that repels insects, and other measures can also be adopted, mainly in closed places, such as cooling the house with air conditioning, use mosquito nets, among others.
Some of the most commonly used substances in topical repellents are
DEET is the most effective repellent currently available on the market, the higher the concentration of the substance, the longer the repellent protection will last, however, when used in children, a concentration of DEET, less than 10%, which has a shorter duration of action and therefore should be applied more frequently, to maintain protection in children older than 2 years.
Some of the products that contain DEET in their composition are:
Also known as KBR 3023, icaridine is a pepper-derived repellent that, according to some studies, has an efficacy of 1 to 2 times greater than DEET, against the Aedes aegypti mosquito.
An advantage of these products is that they have a long time of action, up to approximately 10 hours, in the case of repellents with a concentration of 20 to 25% icaridine.
IR 3535 is a synthetic bioplagicidal that has a good safety profile, making it the most recommended for pregnant women, having a similar efficacy to DEET and icaridine.
This product can also be used in children older than 6 months and has an action duration of up to 4 hours.An example of IR3535 repellent is Isdin mosquito repellent or Xtream spray.
Natural oil repellants contain plant species such as citrus, lemongrass, coconut, soybean, eucalyptus, cedar, geranium, mint or lemon balm, for example, which are generally very volatile and, therefore, in most cases, have a short lived effect.
Lemongrass oil is one of the most commonly used, but it is recommended to apply it every hour of exposure.In addition, some studies show that eucalyptus-lemon oil, in concentrations of 30%, is comparable to DEET by 20%, offering protection.up to 5 hours, thus being the most recommended natural oils and a good alternative for people who, for any reason, cannot use DEET or icaridine.
Non-topical repellents are generally indicated to help topical repellents or in children younger than 6 months who cannot use these products.
Thus, in these cases, the following measures can be taken
These are good options for pregnant women and children under 6 months, see other suitable repellants for these cases.
Although widely used in clinical practice and some of them are approved by ANVISA, some repellents may not be effective enough to prevent insect bites.
DEET-soaked wristbands, for example, protect only a small area of the body, up to about 4 cm from the area around the bracelet, so it cannot be considered an effective enough method.
Ultrasonic repellents, blue light electrical appliances and electrocution instruments have also not been effective enough in several studies.
To be effective, the repellent must be applied as follows
Repellents should only be applied in exposed areas and, after exposure, the skin should be washed with soap and water, especially before bedtime, to avoid contaminating sheets and bedding, thus avoiding a continuous source of exposure to the products.
In places with high temperature and humidity, the duration of the repellent effect is shorter, requiring more frequent reapplications and, in the case of aquatic activities, the product is more easily removed from the skin, so it is recommended to reapply the product when the person leaves the water.