Hornet Stings

IT IS ADVISABLE TO SEEK THE ASSISTANCE OF A MEDICAL PROFESSIONAL ANYTIME SOMEONE IS STUNG. Why They Sting

Stinging insects such as bees, wasps, yellow jackets and hornets use their stings to subdue prey (primarily insects and spiders) and to defend themselves or their colony. While various species display different degrees of aggressiveness, the same basic reasons for attacking and stinging are the instinctive desire to feed themselves or their colony members and to protect and defend their colony.

Appearance and Nest Location

In the United States there is only one true hornet – the European hornet (Vespa crabro). The adult European hornet is approximately 1-1.5 inches long. Its head, thorax, first abdominal segment and legs are reddish-brown. The rest of the abdomen is dark yellow with brownish bands and small spots. European hornet nests are usually built in cavities above ground. Locations such as hollow trees and wall voids are the most common nest sites. However, in rare situations, nests may be built in sheltered, yet somewhat exposed sites. European hornets are not as aggressive as baldfaced hornets, but will nevertheless sting if their colony is disturbed.

Another stinging insect commonly called a hornet are the baldfaced hornets. This species, Dolichovespula maculata is not a true hornet and resembles a larger version of the yellow jacket except they have whitish-colored facial and thoracic markings. Baldfaced hornets build their gray, rounded, paper-like nests high above ground on branches of trees or in hollow trees. Baldfaced hornets are some of the most aggressive stinging insects.

Categories of Reactions and Symptoms

Typical symptoms and reactions to stings by bees, yellowjackets, hornets or other wasps do not differ to a large extent except when a victim is stung multiple times by many individual insects and the victim is highly allergic to the insect’s venom. Generally, hornet stings produce the following reactions and symptoms:

Localized reactions. These are the most common types of reaction to a bee or wasp sting. Symptoms include pain, swelling, warmth, redness at the site of the sting and itching. Symptoms begin almost immediately after a sting and may last a few hours. Large local reactions often come with increased swelling and may last up to a week. Some individuals may experience nausea or fatigue with large local reactions.
  1. These symptoms do not cause major medical problems and are usually limited to or are very near the sting site.
  2. Secondary bacterial infections. This type of skin infection develops if the sting site is frequently scratched and bacteria are given a suitable condition in which to develop. Failure to adequately clean, disinfect and medicate sting sites enable infections to occur.
Systemic (affecting the whole body) allergic reactions. These reactions occur in people or pets that have produced a type of antibody, known as immunoglobulin E, against the same insect venom from a previous sting. Systemic allergic reactions are critical medical issues, but occur in a very small percentage of stings. Symptoms of systemic allergic reactions include swollen red bumps on the skin, flushing of the skin and difficulty breathing due to swelling of the pharynx epiglottis and narrowing of the bronchial passages. The reactions may vary in severity from mild skin to life-threatening. Anaphylaxis, the most severe immunologic reactions, occur more commonly in males and people less than 20 years of age. Severe cases may develop into life-threatening hypotension, which includes low blood pressure, circulatory disturbances, and difficulty breathing. In most cases, anaphylactic reactions occur in individuals who experienced previous stings with minimal reactions. After experiencing an anaphylactic reaction, the risk of a reaction in future stings is above 50%.
  1. Toxins in venom cause toxic reactions, not the body's immune response.
  2. Most often these are due to multiple stings that introduce an unusually large amount of venom into the body. Symptoms can include fever, nausea, vomiting, diarrhea, headache, fainting and convulsions. Swollen red bumps, rash and other skin-related symptoms are less common in toxic reactions than in systemic allergic reactions. Because stinging insect venom is a strong stimulant that causes the immune response, people who have experienced toxic reactions may produce antibodies to the venom and be at risk for future systemic anaphylactic reactions to stings.
Delayed reactions occur, but are uncommon and may show up days to weeks after the sting. These reactions constitute less than 1 percent of all reactions to insect stings. Delayed reaction symptoms vary greatly by individual but may include inflammation of the brain, nerves, kidneys, and blood vessels and blood clotting issues.