Warding Off Insect Bites

For those of us who have recently endured a Midwestern winter, the call of the outdoors beckons as the thermometer rises and the days lengthen. During several recent early summers, though, record rains have yielded a bumper crop of mosquitoes ready to join the ranks of ticks and stinging insects looking to make a meal of those of us eager to enjoy the warmth of the sun and the fresh air. Happily, a few simple measures can lead to effective prevention, and when needed, there are simple treatments to lessen the discomfort and accelerate healing from insect bites.

Begin by reducing the risk of mosquito infestation at your home. Standing water in eaves troughs and pools of water are ideal breeding grounds that can be eliminated. Surprisingly, mosquitoes are also harbored in your lawn. Keeping the grass short is a very effective measure to diminish their numbers. Look as well for wasps and other stinging insects and their nests under the eaves, beneath decks, and where pipes or wires enter your home. Call a professional exterminator if you discover any of these less-than-hospitable guests.

There are several protective measures you can take when going out to keep insect bites at a minimum. Wear light-colored clothing because it's easier to see insects when they alight, giving you the opportunity to shoo them away before they can do any harm. Cover as much of your body as is practical in light of the temperature. Wear a hat for both protection from the sun as well as stinging insects.

When hiking in the forest or tall grass, preventing tick bites is paramount. This can best be done by wearing long-sleeved shirts and long pants with the cuffs tucked into your socks. In addition, conduct a careful body check afterwards to look for ticks, paying special attention to any part of the body covered with hair and any skin folds. Keep in mind that a deer tick is much smaller than the more common wood tick and is harder to spot. If the tick has not had a blood meal, the infection with Lyme disease is unlikely.

Insect Repellent and Bite Treatment
DEET (n-diethyl-m-toluamide) is still the most effective chemical that is safe for skin application to prevent both tick and mosquito bites. DEET has been in existence since 1957, and when used at a strength of 30% or less, is still acceptable. Problems arise in the elderly and children when concentrations higher than 10% are used and when the lotion is applied over a large surface area. A lotion is better than a spray because the application can be better controlled. Do not let small children apply the lotion themselves and do not apply it on their hands where they may accidentally ingest it. Keep it away from the mouth, lips and eyes, as well. A single application is all that is necessary unless one has been swimming or actively perspiring.

Citronella is an alternative to DEET, and although potentially less toxic, it is only 10-15% as effective as DEET and may require frequent reapplication. For picnics and backyard gatherings, coils and repellent candles are a safe alternative to commercially available sprays that aerosolize chemicals. Remember also that perfumes, colognes and perspiration will attract insects.

Treatment for mosquito bites can include a topical antihistamine such as Caladryl, a cool, moist compress or a bath in lukewarm water. An oral, over-the-counter antihistamine such as Benadryl may be effective, or for less drowsiness, ask for a prescription for Claritin or Allegra. Keep fingernails cut in small children so if they scratch, they do less damage to the skin. Watch for secondary infections at the location of bites from excessive scratching, indicated by worsening redness, swelling and a cloudy discharge. If this occurs, begin by washing with soap and water and consider a topical antibiotic before seeing your doctor.

Stings from bees and wasps are potentially more serious and need to be respected. If a stinger remains in the wound afterward, carefully attempt to remove it by scraping gently with a credit card, ruler or butter knife. (If you try to pull the stinger out with fingers or a tweezer, you will probably cause more toxins to enter the skin.) Follow this with a cool compress and a topical antihistamine if needed. You may want to use an anti-inflammatory medication if the pain or swelling is significant. If you have a history of allergic reactions, always carry a bee sting kit with you (in case of anaphylaxis) and renew it annually.

Although the risk of contracting Lyme disease from tick bites is low in most of our larger cities, anytime you are in contact with brush or forest the potential for tick bites exists, especially from April to September. Take the necessary precautions, and see your health care provider if you experience symptoms after being bitten.

This is a great time to be outdoors and active. Take a few moments to familiarize yourself with the health and safety essentials that will help you fully enjoy a safe and healthy summer.

Russell G. Robertson, MD
Associate Professor Family & Community Medicine
Medical College of Wisconsin

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.