David Poon, BSc Immunology and Infection, PharmD Student
I Hate Mosquitoes
There, I said it! I’m sure there’s a reason why they exist. Maybe they’re important for some food web out there. But to me, mosquitoes are carriers of viral diseases, such as West Nile, Dengue, and Zika. If that wasn’t enough, they can also carry parasites that cause malaria. Luckily, here in Canada, these diseases are rare with only 7 cases of West Nile Virus in Alberta last year.1
Why is My Skin So Itchy
You can blame the secretions found in mosquito’s saliva for this. Our body’s immune system releases histamine once it sees a foreign substance enter our body, such as the saliva from a mosquito.2 Histamine is what causes the red, swollen and itchy bump that we call a mosquito bite. Typically, a mosquito bite lasts between hours to days. Some people make antibodies against the secretions found in the saliva of mosquitoes, and this causes larger welts that last for several days. Like with all insect bites, there is a slight chance that anaphylaxis could occur, but this chance is quite rare compared to other insect bites like wasp stings.
Preventing Mosquito Bites
You’ve probably heard your parents tell you some of these things in the past. Or maybe your best friend Jimmy (sorry to all the Jimmy’s out there) told you that the best way to prevent mosquito bites is to do the macarena dance. Let’s see how right they were.
#1 Use bug spray
It’s recommended to use bug spray and apply it to your clothes and skin, but avoid spraying directly on your face. Instead, spray it into your hands and then apply to the face, avoiding the eyes and mouth. As a rule of thumb, never use bug spray in infants <6 months old. When using sunscreen (SPF 30 or higher is recommended), apply sunscreen first and then bug spray second. For all the chemicals found in bug spray discussed below, please follow the instructions on the spray:
- DEET smells and tastes terrible to mosquitos. Higher concentrations of DEET lasts longer and can be reapplied less frequently. For example, 30% DEET lasts between 5-8 hours, while 5% DEET lasts between 1.5-2.5 hours.
- Icaridin (A.K.A. picaridin) is thought to mask the pheromones released by humans or change how mosquitoes smell those pheromones. This would be the first choice for children 6 – 12 months old. Again, higher concentrations last longer, with the 20% strength lasting 7 hours and 10% lasting 5 hours.
- p-menthane 3, 8-diol (PMD) is oil of lemon eucalyptus and lasts about 2 hours.
- Oil of citronella smells and tastes terrible to mosquitos, but only lasts about 20 minutes to 2 hours, depending on the concentration used.
- Soybean oil masks pheromones released by humans and/or cools the surface temperature of the skin. It works as well as 10% DEET and lasts about 1-4 hours.
#2 Type of clothing
While many people believe otherwise, the colour of your clothing – white, black or neon – doesn’t matter much. What’s important is wearing clothing that covers as much of your skin as possible such as your arms and legs. This is especially important for children, since some bug sprays shouldn’t be used in children.
#3 Avoiding certain areas
Avoiding areas with tall grasses, marshes, swamps, busy areas and avoiding being outdoors at dawn and dusk may be advisable to avoid mosquito bites. Standing water, such as bird baths, clogged gutters, or buckets of water for gardening, is a breeding ground for mosquitoes. So, if you plan on spending your time outdoors, keep an eye out for these spots.
Best Ways to Treat the Itch
There are many home remedies you may have heard about on the internet or have tried yourself to relieve the itch ass opiated with mosquito bites. Some may work and others not so much. We’ll go through a few common products people might select over the counter at their local pharmacy.
- Hydrocortisone Cream (0.5% or 1%) is a weak steroid cream that reduces itchiness and inflammation.
- Apply three to four times a day as needed for up to 7 days.
- Avoid use near the eyes, if the affected skin is broken or if an infection may be present.
- Calamine Lotion reduces swelling and inflammation and has a soothing effect on the skin.
- While you may apply liberally as needed, lower strengths are preferred.
- Avoid use if the affected skin is broken and an open wound is present.
- Pramoxine (1%) is a weak local anesthetic that reduces sensation in the skin.
- You may apply up to four times a day as needed, while avoiding areas near the eyes and nose.
- Ammonia/baking soda are chemicals found in Afterbite™, which you might have seen advertised at various stores or pharmacies. It has a cooling effect that may help relieve some of the itching.
- Apply sparingly as needed, while avoiding areas near the eyes and mouth.
- Avoid in children <2 years old.
The Bottom Line
I hope you find this knowledge powerful in your quest to avoid and treat mosquito bites in the spring, summer and years to come. If you have questions, speak to your local health care professional in order to find the best product for you or a loved one.
We hope you took away something valuable from this piece. If you have any questions or concerns regarding this article or others, feel free to reach out to us on Instagram, Facebook, or at firstname.lastname@example.org with your feedback. We’d love to hear from you.
- Alberta Health. (n.d.). West Nile Virus Surveillance in Alberta. Retrieved from http://www.health.alberta.ca/health-info/WNv-evidence.html
- Kleiman, N. (2016). Insect Bites. RxTx.
- Prevent Mosquito Bites. (2018, March 19). Retrieved from https://www.cdc.gov/features/stopmosquitoes/index.html
- Mosquito Avoidance. (2018, June 1). Retrieved from http://www.dynamed.com/topics/dmp~AN~T115142/Mosquito-avoidance