Should I be Worried about Mosquitos?

Q: I noticed the bugs are starting to come out. Should I be worried about mosquitos?

A: Anyone who has spent significant amount of time outdoors in Wisconsin has surely experienced the effect of a mosquito bite.  Often these bites are a minor nuisance and result in a skin reaction that is comprised of swelling and itching.  However, on more rare occasions these bites can be much more concerning, as they may cause allergic reactions or even insect-borne illnesses such as West Nile virus.

Prevention, or at least reduction, of mosquito bites can be accomplished by measures that help eliminate exposure and by additional measures that can actively repel mosquitoes.  Such activities include:

Staying indoors at dawn and dusk.

  1. Avoiding wetlands, bush and tall grass.

  2. Eliminating standing water around the home environment in order to reduce breeding grounds for mosquitoes.

  3. Making sure screens on all windows and doors are well maintained.

  4. Using insect repellents such as DEET or picardin.

  5. Consider wearing permethrin-impregnated clothes or applying this insecticide to such fabrics as tents and sleeping bags.  This should never be applied directly to your skin.

Insect repellents come in a variety of formulations and concentrations. The most common is DEET (N,N-diethyl-3-methylbenzamide), and the most effective repellents are DEET and picardin. Other repellent agents such as PMD (P-methane-3,8-diol), BioUD and IR 3535 tend to be less effective. Additionally, other substances or devices such as citronella, botanical oils, herbal remedies, electronic devices and impregnated wristbands have been studied, but they tend to be very ineffective and their use is discouraged.

DEET-containing products provide excellent protection against mosquito bites. Concentrations of DEET range from less than 10% to 75%, but the effectiveness of DEET seems to plateau at about 30%. The higher the percentage of DEET, the longer the duration of effect:  10% DEET lasts about 2 hours, whereas, 24% DEET lasts about 5 hours.  DEET concentrations of 10-30% can be safely applied to children when used according the product directions. The American Academy of Pediatrics states that children less than 2 months of age should not use any DEET containing products. In rare circumstances, overuse or misuse of these products can lead to adverse neurologic effects.

Picardin, a plant derived compound, is another repellent used and it has a similar efficacy to DEET for short periods of time, however, DEET seems to have a longer duration of effect. Picardin does not seem to have any risk of neurotoxicity and is generally well tolerated. Some people prefer picardin over DEET because it is odorless, non-sticky, non-greasy and does not irritate the skin. Picardin is not recommended for children under 2 years of age.

It is important to keep in mind these tips when applying mosquito repellents:

  1. Use just enough to lightly cover the skin but do not saturate the skin.

  2. Apply to exposed skin, clothing or both, but not to skin under clothing.

  3. When applying to the face, first apply to your palms and gently rub your palms together, then apply to your face.

  4. Always wash repellent from your palms to avoid contact with your mouth or eyes.

  5. Do not apply over wounds, cuts or irritated skin.

  6. Do not inhale the aerosol.

  7. Do not spray in confined spaces.

  8. Be certain to avoid spraying it into your eyes.

  9. Do not apply to the hands of small children.

  10. Frequent reapplication is not necessary.

  11. Wash the repellent off with soap and water once it is no longer required.

  12. Avoid products that contain both DEET and sunscreen in children because reapplication (as may be needed for the sunscreen component) can result in excessive exposure to DEET.

If all the prevention measures fail and you do happen to develop a reaction to a mosquito bite consider these treatment options:

  1. Wash the area with soap and water.

  2. Use ice packs to decrease the swelling.

  3. Use topical anti-itch creams.

  4. Consider oral antihistamines (Benadryl, Zyrtec, Claritin, etc…).

  5. Consider topical steroid creams (1% hydrocortisone [OTC] or other prescription creams).

  6. Oral steroids (Prescription only and used for the most severe reactions).

By Luke Tremble, MD, pediatrician at ThedaCare Physicians-Pediatrics in Appleton.