INSECT STINGS AND BITES

With warmer weather comes the expected spring & summertime nuisance of insect stings and bites. Stinging insects include honeybees, wasps, hornets and yellow jackets. Biting insects include mosquitoes, fleas, flies, chiggers, ticks and spiders.

Insect stings usually result in a local skin reaction as a result of venom injected by the stinger. A reddened, painful area with an itchy sensation may develop that lasts about 4-5 days. Infection can develop from scratching. Multiple stings can result in a more generalized reaction that includes vomiting, diarrhea, generalized swelling and collapse. Stings in the mouth and throat are of special concern because local swelling may block the breathing passages. The most dangerous reaction to a sting is a severe allergic reaction called anaphylaxis. Symptoms include hives, flushing, itching, face and neck swelling, nausea, fever, and shortness of breath. Anyone with suspected anaphylaxis or who is having difficulty breathing after an insect sting should be taken to the nearest emergency department immediately. Transport via ambulance (EMS) may be necessary.

Insect bites are usually less painful than stings, with small skin reactions that don’t last long. Transmission of disease is more of a concern with insect bites. Mosquitoes bite more people than any other blood-sucking insect. Saliva injected into the host as the bite occurs may transmit a virus that causes encephalitis, an inflammation that affects parts of the brain and spinal cord. Mild cases of encephalitis may cause fever and a headache. Severe infections usually have a sudden onset of symptoms that include headache, high fever, stiff neck, confusion, tremors, convulsions (especially in infants) and (rarely) paralysis. Horse, deer, stable, sand and black flies are some of the flies that are capable of biting.

Most fly bites are painful, but short-lived. Inflammation and itching is similar to that associated with mosquito bites.

Ticks are parasites that feed on the blood of warm-blooded animals, including humans. Their bite is usually painless with little or no local reaction. The tick will remain attached until it becomes engorged with blood and releases its hold on the host, which can take up to ten days. Two diseases that can be spread by ticks are Rocky Mountain Spotted Fever (RMSF) and Lyme disease. Rocky Mountain Spotted Fever is caused by bacteria that grow inside the tick and are passed on when the bite occurs. Symptoms include high fever, headache, rash, fatigue and muscle aches. RMSF can be fatal if left untreated. Lyme disease is also caused by a bacteria and early symptoms include a rash at the bite site. A rash around the bite site can occur seven days or more later, along with fatigue and a mild vague illness. Late symptoms include arthritis, nerve and heart disorders.

Chiggers are really mites, which are more closely related to spiders. The immature form (larvae) are bloodsuckers and will feed until engorged and then drop off. The adult usually attaches at the base of a hair follicle at which time they inject a digestive fluid that dissolves cells to provide its meal. Bites resemble that of a mosquito, but are usually found under areas of protective clothing.

All spiders are carnivorous and use venom to subdue prey. Digestive fluids in the venom predigest the food/tissue to a liquid state, which is then sucked up by the spider. Spider bites frequently result in local tissue inflammation and breakdown.

While many spider bites are attributed to the Brown Recluse Spider, few cases can actually be attributed to this particular spider. The Brown Recluse prefers to live in dark, dry, quiet places and comes into contact with humans only when disturbed. It is about one and a quarter inches long and is dark tan with a violin shaped marking on its back. The center of a Brown Recluse bite progresses from a blistered area to a red, then black appearance with surrounding redness and swelling. It is often referred to as a “bulls eye” appearance. Rare reactions involve the blood and kidneys.

The Black Widow Spider can be identified by the black body and orange hourglass shape on the underside of the abdomen. Only the female is venomous. Although the bite is usually painless, intensemuscle cramping and pain often occur within an hour of the bite. Other symptoms include a burning sensation in the soles of the feet, slurred speech, headache, dizziness and fever. Deaths are very rare, but recovery may take several days. Black Widows are generally found only in the most southern parts of Indiana.

Reducing your exposure to insects and arthropods should be your number one priority. This can best be accomplished by covering exposed skin with clothing and avoiding bright colors that attract nectar-gathering insects. Tuck pant legs into socks and tuck in shirts and stay away from areas with lots of weeds and blooming plants that attract bees and wasps. Garbage and food also attract these scavengers. Stay on paths when in the woods, avoiding underbrush. When camping, place your campsite away from hollow logs and caves where mosquitoes congregate. Take advantage of screening, nets and enclosures. Beware of open drink containers that can easily conceal a stinging insect. Remember, stinging is a defensive action on the part of the insect that usually occurs when the insect is threatened. Avoid rapid movements when a stinging insect approaches.

Insect repellents with DEET (N-N-Diethyl-m-toulamide) are available in a variety of concentrations and are considered safe if used according to directions. Use formulations with less than ten percent DEET, especially on small children. Apply the repellent to exposed skin, avoiding your face. Spray the repellant into your hand and apply it carefully to your face with your hand. DEET can be absorbed through the skin and repeated application without removal can result in toxicity. Thoroughly wash DEET off exposed skin with soap and water when the repellent is no longer necessary. Signs of DEET toxicity include headache, confusion, tremors and, very rarely, seizures.

Most stinging insects, except honeybees, withdraw their stinger after a sting. Examine the site and if a stinger is present, scrape it out with the edge of a credit card or dull utensil. Grasping the end of the stinger may inject more venom into the sting. Wash the area gently with soap and water. Most venoms have an acid component and applying a baking soda paste at the site will neutralize and minimize discomfort. A cold compress can also be applied over the paste. Be careful to prevent frostbite by avoiding direct contact of ice to the skin.

Ticks can be removed by gently grasping the body of the tick as close to the skin as possible with tweezers or your fingers protected by tissue. Pull the tick off with a slow, steady pressure. If the head breaks off in the skin, seek medical help for removal. Wash your hands and the area with soap and water after removing the tick. Spider bites should be cleaned with soap and water. Warm compresses several times a day and a topical antibiotic ointment can be applied, if needed.

Signs of ulceration or infection warrant medical attention.

Next entry: E-Cigarettes

Previous entry: Mushrooms