In Quebec, with the return of the warm weather comes the return of the insects. From May to September, we have to deal with a whole slew of little beasties that have one thing in common: they bite or sting! Mosquitoes, bees, wasps, black flies and biting midges can turn a pleasant summer outing into pure agony.
Each species has unique behaviours, along with favourite seasons and habitats. Mosquitoes, for example, are mainly present in June and July. Their buzzing can be particularly bothersome and they have the ability to sting through clothing. They are generally harmless, but they can sometimes transmit diseases, including the West Nile virus.
Black flies, for their part, are especially fond of areas where there are a lot of coniferous trees. Deep woods enthusiasts must deal with this insect until the month of September. It is smaller than mosquitoes and is able to sneak into clothing. They have a predilection for the more shaded areas of the body, such as behind the ears, on the neck and on the ankles.
Biting midges (also called “no-see-ums” or sand flies) are known for the burning sensation that follows their bite. They are present from the end of May to July, during which time they are active 24 hours a day, with a remarkable energy surge in late afternoon. While they are too small to bite through clothing, their small size allows them to pass through screens.
Bees and wasps are probably the most feared of all stinging insects. Larger in size, they have a retractile stinger located at the posterior extremity of their abdomen. Bees only sting once and leave their stinger in the skin, while wasps can sting repeatedly, since their stinger is smooth and does not get stuck in the skin. In both cases, the bite is painful and uncomfortable.
Normal, benign reaction
Thankfully, insect bites are usually benign. They typically cause local swelling or puffiness, itchiness or a burning sensation. Bites on the eyelid tend to produce more significant swelling. Symptoms decrease on their own after a few hours or days.
In most cases, the recommended treatment is to clean the affected area with soapy water. If the stinger is visible, it can be removed using tweezers (preferably disinfected). Applying moist cold compresses is an easy and effective way to reduce the pain and swelling.
There are several products on the market to relieve the symptoms of an insect bite: analgesics, calamine lotions, antihistamines and skin antiseptics. Your pharmacist can help you choose the right product for your specific needs. In all cases, however, it is important not to repeatedly scratch at the wound, as this could cause a skin infection.
There are two types of reactions to insect bites. The first, very common, involves a simple local eruption as described above. But there is another possible reaction, the rarer and potentially deadly anaphylactic shock, which indicates the presence of an allergy to the insect venom. It is estimated that less than one percent of the population has this condition, which constitutes a medical emergency.
Being able to recognize this type of reaction is crucial in order to be able to react quickly and appropriately. The symptoms of anaphylactic shock include agitation, significant itching, widespread skin eruptions, facial swelling, a drop in blood pressure and an increased heart rate.
If untreated, an anaphylactic shock can prove fatal within five to fifteen minutes. This is why individuals who have ever had a severe allergic reaction to an insect bite should always carry an adrenaline autoinjector system (e.g. : Epipen®). It is essential for allergic individuals and the people around them to know how to administer this product. If an anaphylactic shock were to occur, it would be too late to start reading the label…
Preventing insect bites
Some precautions can be taken in order to avoid or limit insect bites. The first effective measure is to wear adequate clothing. Preferably wear thick but loose clothes that have a hood and that close at the neck, wrists, waist and ankles. Avoid shiny materials and dark colours, opting instead for light-coloured clothing. Zippered clothes protect better than those with buttons.
You should also avoid wearing perfume or fragrant lotions, as floral or plant-based scents are thought to attract bees, wasps and mosquitoes.
Allergic individuals must be particularly careful. They are advised, for example, to never walk barefoot in the grass and to avoid strolling or picnicking near beekeeping areas. The best possible prevention is always to avoid any high-risk situation.
There are also various products with insect-repellent properties on the market. When purchasing such an agent, make sure to choose one that is approved in Canada and to read the label before applying the product.
Experts usually recommend DEET-based agents, which come in different concentrations. Research has shown that products containing low concentrations of DEET are as effective as those containing higher concentrations, although their protective effect is shorter-lived.
Therefore, a 30 percent concentration will be effective for six hours, whereas one that has a 10 percent concentration will offer protection for three hours. Base your selection of a product on the length of exposure as well as on the age of the user.
This last point is important, as products containing DEET must not be used on babies under the age of six months. As for children between the ages of six months and two years, using DEET should be avoided, unless not using the product presents a high risk of complications. In such cases, you can opt for a product with a 10 percent concentration, applying only it once a day and in small quantities. In children between the ages of two and twelve, using the lowest-concentration product (10 percent) is recommended, with a maximum of three applications per day.
Pregnant women should take certain precautions when using DEET. While there is no formal evidence that using this product is dangerous for the fetus, the few studies available on the subject compel us to instead favour the use of physical barriers, like clothing or netting, to limit risks.
Incidentally, the information on the safety and efficacy of other types of products (e.g. citronella, vitamins, etc.) is scant and sometimes contradictory. They should be used with caution.
Lastly, it is good to know that DEET can decrease the effectiveness of sunblock. You should therefore apply sunblock at least 20 minutes before applying the insect repellent.