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Author: Phillip J. Gonzales, M.D.
Clinic: Woodbury Clinic

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When you or a family member are stung by or bitten by an insect or spider, your ability to recognize the culprit can be important toward helping you and your physician initiate treatment. Also important is how to avoid being stung or bitten. A useful handout- Insect Stings: What You Need To Know, can be obtained by contacting Dr. Gonzales at the addresses found at the end of this article. Here are a few facts about common flying, insects and spiders found in our region of the U.S.

 

      Flying Insects- Insects called Hymenoptera include winged insects such as yellow jackets, hornets, paper wasps, and honeybees. All of these insects puncture the skin with a hollow stinger through which they inject their venom, In the U.S., yellow jackets are the leading cause of allergic reactions to insect stings. They build their nests in the ground, hollow logs, and caverns, and are attracted to food, drink, and garbage. Hornets build large paper nests in trees and bushes. Paper wasps build honeycomb paper nests, typically under the eaves of buildings or in trees and bushes.   Honeybees, which live in colonies that may last for years, usually do not sting unless provoked. Africanized honeybees, also called, "killer bees", are more likely than other honeybees to swarm, but their venom is no more potent.

 

      Most Hymenoptera stings result in pain, swelling, redness, and itchiness in the area around the sting site. These signs and symptoms constitute a normal local reaction, which will normally improve within a few hours. Normal local reactions need only wound care and symptom management. If one still has the insect's stinger in his skin, remove it as quickly as possible by scraping it with a fingernail or credit care, or use tweezers, if necessary. Since a stinger can continue to inject venom even after the insect is gone, how you remove it isn't as important as getting it out quickly. Clean the sting site with mild soap and water, apply ice to the area to reduce swelling, and administer an analgesic such as ibuprofen or acetaminophen to address the pain. An antihistamine, such as diphenhydramine (Benadryl), which is available as a pill, spray, or cream, can help alleviate itchiness. Some people who are stung (17-56%) will have a large local reaction, with more extensive redness and swelling that continues to enlarge for one or two days before slowly resolving over several more days. Any person who has been  stung could develop a bacterial infection at the sting site, but this is rare, Infection is more common in

children who scratch with dirty hands and in people with weakened immunity to infection. If this happens, antibiotics will be necessary. If any person develops a severe

allergic reaction, with signs and symptoms of difficulty breathing, swallowing, or severe rash and swelling, evaluation in the Urgent Care or hospital emergency department may be necessary.

 

       Spiders- Of the 20,000 spider species, only two in the U.S. pose a danger to humans- the brown recluse and black widow. Both can cause serious illness, but they very rarely cause death. It is estimated that spider bites cause fewer than three deaths per year in the U.S.

 

       The Brown Recluse spider is found mainly in the Southeast and the Midwest. They are hairless and have a leg span of one inch. They are tan to dark brown and have a characteristic violin pattern on their head and rear quarters. These spiders live in warm, dark, dry locations, such as attics, garages, closets, and basements, where they spin small,

 haphazard webs. They bite only when threatened.

 

 Their venom contains an enzyme that disrupts the skin's protection and can lead to skin breakdown; it is extremely poisonous. Fortunately, though, these spiders inject only a very small quantity of venom into their victims. The bite is initially painless, and you may not know you were bitten until symptoms develop two to eight hours later. Symptoms include severe pain and itchiness at the bite site, nausea. vomiting, fever, and muscle aches. Initially, the site is mildly red, but the redness turns to paleness surrounded by a red ring, which is known as a "bull's-eye" appearance. The center area often blisters, forms a crater, and turns black as the tissue dies.

 

 The person may be left with a large area that takes weeks to heal. Treatment is to wash the area thoroughly with mild soap and cool water. Apply a cold pack, elevate the wounded body part, and administer analgesics and antihistamines. In rare cases, a person bitten by a brown recluse will develop severe lesions or total body symptoms requiring hospitalizations.

     

     The other spider that poses a danger to humans is the Black Widow spider. The black widow has a leg span of about one inch and is found throughout the U.S. The northern black widow, which can be black or brown, has a row of red spots down the middle of its upper abdomen. All black widows are nocturnal and contain venom. They inhabit the undersides of rocks, plants, and debris. They will bite if their web is disturbed or they get caught in shoes or clothing. Although black widow spider bites can be painless, the first symptom is often at the bite site.   The pain is followed by localized muscle cramping, abdominal pain, weakness, and, sometimes, tremors or shakes. Treat a person who has only minor symptoms by cleaning the bite site, applying a cold pack, elevating the wounded body part and administering analgesics. For a very few people, symptoms may progress to nausea, vomiting, dizziness, and/or severe pain. These individuals should seek immediate evaluation in the Urgent Care or a hospital emergency department. A black widow bite rarely causes death.

 

To request more valuable information in the handout, Insert Stings: What You Need To Know, access our website at www.minnhealth.com