Ask the Pharmacist

Q. Now that summer is approaching and the pandemic is hopefully nearing the end, I have a few hiking and camping trips planned. Is there a product you recommend to keep the insects away?

A. We covered this topic so many years ago so it is a great idea to review it once again.

First and foremost, be sure to have the appropriate attire for your hike since being clad in a bikini or other swimwear will obviously give the “biters” much more flesh to target. Instead, wear long socks, long pants that can be tightened at the ankle (or tuck your pants into your socks), a long sleeved shirt and a sun hat. The less exposed skin the better (this is also important given the increasing incidence of lyme disease that we are experiencing here in Ontario). However when you are deep in the woods enjoying nature, the mosquitos can quickly dampen the mood even if you are dressed properly.

Many of you might be very familiar with DEET (N,N-Diethyl-meta-toluamide) products as they have been around for decades. DEET has been proven to be very effective and safe, if used properly. Adults and children 12 and up, can use up to 30% DEET whereas children aged 2 to 12 years can use DEET to a maximum strength of 10%. Both of the age groups can apply/use these products up to three times daily. For those aged 6 months to 2 years, they are also limited to a 10% DEET product however they are limited to only 1 application per day. Babies less than 6 months old are to avoid DEET products and the parents/caregivers are to rely on the use of mosquito netting over strollers and cribs.

The protection you can expect from DEET against mosquitos, black flies and ticks depends on the strength applied;

10% = up to 4.5 hours
20% = up to 6.5 hours
30% = up to 8 hours

Many people complain about the odour associated with DEET repellents as well as the oily/greasy feeling it leaves on the body. Not only that, it has been known to damage some clothing fabrics which can be quite a nuisance. On a more serious nature, DEET has been associated with toxic encephalopathy which is a brain dysfunction caused by toxic exposure to a substance, in this case DEET. This is more associated with prolonged or excessive use or accidental ingestion and can be prevented by adhering to the appropriate dosage stated above, applying in a well-ventilated area, washing the skin and clothing afterwards and keeping the product away from children.

For those looking for alternatives to DEET repellents, there are other options. Repellents containing Icaridin have been available for many years and are generally known to be as effective as DEET products. Icaridin 20% can be used for adults as well as children 6 months of age and older. As with DEET repellents, the protection depends on the strength of the product being applied;

  • 20% = up to 8 hours against ticks & black flies and up to 7 hours against mosquitos
  • 10% = up to 7 hours against ticks & black flies and up to 5 hours against mosquitos

It is interesting to note that the 20% icaridin repellent gives longer protection than the lower concentrations (10%) of DEET products and can be used safely in all age groups over age 6 months. Because of this, icaridin 20% is the first line choice of repellent in children aged 6 months to 12 years. Another advantage of icaridin over DEET is the lack of odour, oily/greasy feeling and the fact that it does not stain clothing.

In both cases, DEET and icaridin are not recommended to anyone under 6 months of age however their 10% product may be considered for babies less than 6 months of age if travelling to an endemic area outside of Canada and physical barriers are not an option.

Another repellent that can be considered contains Oil of Lemon Eucalyptus. For many people that choose to not use such harsh chemicals on skin and clothing, this can be a great alternative. Though this option might be a good natural choice to use, it is important to note that it can only be used in anyone over the age of 3 years old. It can also cause skin reactions in those individuals known to have skin issues such as allergic dermatitis/ eczema.

As well, the Oil of Lemon Eucalyptus has a short duration of action of 2 hours against mosquitos and up to 5 hours against black flies and may be applied twice in a 24 hour period. That might prove to be just long enough if you are out on a patio for an evening and can easily retreat indoors but perhaps not if you plan to go on a long hike in the wilderness.

As for other natural alternatives, there are repellents that contain soybean or citronella which unfortunately may not give adequate protection against ticks which appear to be an ongoing concern in many areas (note that Deet, icaridin & oil of lemon eucalyptus are all effective at repelling ticks). A 2% soybean oil can offer up to 3.5 hours of protection against mosquitoes and up to 8 hours against black flies with no age limits and no restrictions on how often to apply. On the other hand, citronella products can offer a range of protection of 30 minutes to 2 hours against mosquitos and should not be applied to infants and/or toddlers.

Often when we are outdoors and requiring protection against the various insects, we also need to protect ourselves against the sun. In these cases, it is recommended to apply the sunscreen first and allow time for it to adhere to the skin and then apply the repellent of choice. Since sunscreens need to be applied liberally and frequently (every 2 hours) and repellents should be applied sparingly and infrequently (1 to 3 times daily depending on the type), it is advised not to use a combination sunscreen/repellent product. Some further do and don’ts follow to ensure the safe use of repellents regardless of which product you opt for;

· Spray product in a well-ventilated area
· Do not spray directly to face or on children; rather spray on your hands and apply
· Do not apply repellent under clothing as this may increase absorption into your body
· Do not apply to an area of skin that is cut, open wounded, sunburned
· Wash repellent off once indoors and change clothing

For more information on this or any other health related topic, contact your pharmacist.