Erie County Medical Society

May 29th, 2013

You Can Fight Mosquito Bites

If you’re not an entomologist, you probably dislike mosquitos.   These little critters can pose significant health hazards.  They can spread viral encephalitis, yellow fever, dengue fever, bancroftian filariasis, epidemic polyarthritis, West Nile virus, and malaria.

So the arriving summer is a good time to review your anti-mosquito game plan.

First, avoid attracting mosquitos.  These little pests love floral fragrances found in perfumes, soaps, and hair care products.  So, if you don’t like the company of mosquitos, avoid these fragrances like … well, like the plague … yet another insect transmitted disease. 

Mosquitos are also attracted by dark clothing and the smell of alcohol on the breath.  These are two more things to avoid.

Unfortunately, insects are attracted by skin warmth and perspiration as well as by lactic acid and exhaled carbon dioxide, all factors that are difficult to control.

Mosquitos are most active between dusk and dawn hours.  So it is best to avoid being outdoors at these times.

Insects are also attracted by flowers, bushes, trees, and piles of wood.  So if you’re in the woods, stick to the clearings and paths.

Exposed food attracts mosquitos.  Keep food well covered to avoid these uninvited arthropods.

Second, use physical barriers against mosquitos whenever possible.  Long sleeves and long pants are a good place to start.  It is even better if pant legs are tucked into boots or socks.  Closed or screened windows in the home and closed windows in the car also limit intrusion from insects.  While mosquito netting is of limited utility outside the tropics, it is still a practical solution for covering baby carriages.

Third, use insect repellant.  While insecticides kill insects, repellants only deter them from biting.  Repellants do not envelop the user in an invisible aura, they only protect the area to which they are directly applied. 

Most repellants can and should be applied to skin and clothing as mosquitos can bite through thin cloth.  But, no repellants should be applied under clothing.  Lastly, check all labels to ascertain that a particular product will not harm a specific fabric.

Permethrin is a repellant and insecticide that should be applied to clothing only, not skin.  Its effect lasts through several washings.

The most effective insect repellants are those containing DEET, Picaridin (KBR 3023), or oil of lemon eucalyptus (PMD).  These are available in varying concentrations.  The higher concentrations are not more effective in repelling insects, they just have a longer duration.  If you don’t anticipate being exposed for a prolonged time, choose a lower concentration.  You can always reapply the repellant if you begin experiencing problems.  Use soap and water to wash off the repellant when the exposure is over.  Ingested garlic, brewer’s yeast, and thiamine are not effective at repelling insects.

When using sunscreen as well as repellant, it is better to apply the sunscreen first.  Since sunscreen typically needs to be reapplied more frequently than repellant, it is better to use separate products rather than an all-in-one preparation.

When applying repellant, avoid the eyes and mouth as well as any broken or irritated skin.  Again, do not apply repellant under clothing.  Avoid spraying repellant in enclosed spaces.  A light spray is sufficient; sprayed repellant should not run down the skin.  If repellant gets into the eyes, flush with copious amounts of water; and, taking the product with you, seek attention at the emergency room.

Oil of lemon eucalyptus should not be used on children younger than 3 years, and products containing DEET should not be used on infants younger than 2 months.  Use the products specifically formulated for children.  These preparations have lower concentrations of potent ingredients.

Do not allow children to apply repellant themselves.  Neither should you spray repellant on a child; spray on your hands and then apply to the child’s skin, carefully avoiding the child’s eyes, mouth, and hands (since children are prone to putting their hands to their mouths).  Application by hand instead of by spray also applies to facial application in adults.

• Finally, if you do get bitten remember these simple steps:
• Wash the bite with soap and water.
• Don’t scratch, although the bite may itch.
• Ice can temporarily relieve the itch; but, don’t apply ice or an ice pack directly to the skin, interpose a towel.
• Application of a topical corticosteroid can help alleviate the itching and inflammation; but, follow directions carefully and apply only to small areas.
• Avoid topical antihistamines or local anesthetics except on the advice of a doctor, since some of these preparations can occasionally induce contact sensitivity reactions.
• An over-the-counter 3.5% ammonia product called AfterBite relieves the itch of a mosquito bite.  It should not be used near the eyes or on children under the age of 2 years.
• For severe or unusual reactions to mosquito bites, see your doctor.

The Erie County Medical Society hopes that these tips help you enjoy a more pleasant summer.  So, have fun this summer, but don’t get bitten!

Thomas Falasca, DO

Enjoy this informative video by Rose Eveleth from TEDEd!