What is Hymenoptera Stings?
The Hymenoptera group is made up of over 150,000 different types of insects, some of which can fly and some that can’t. Certain insects in this group have specially adapted ovipositors (parts used in reproduction by female insects) that can also be used as stingers. In most people, the stings from these insects only cause local swelling. However, these stings are also responsible for the majority of deaths in the United States caused by venomous injuries. These deaths typically happen due to severe allergic reactions and a type of severe allergic reaction called anaphylaxis.
This discussion will mainly focus on the three most common and medically significant types within this group: Apidae (bees), Vespidae (wasps, yellow jackets, hornets), and Formicidae (specifically, fire ants). Each of these insects uses their specialized ovipositors, or stingers located in their abdomen, to inject venom into their targets either for capturing prey or for self-defense.
What Causes Hymenoptera Stings?
The Apidae family, which includes honey bees, bumblebees, and others, usually won’t attack unless they feel threatened. However, there’s a type of bee labeled as “Killer Bees” or “Africanized bees” that are known to be very defensive and can even behave aggressively. They are widely known for their swarming tendencies. These bees first appeared in Brazil in the 1950s and have since made their way to South and North America, particularly the Southwestern United States. They are considered invasive and are responsible for a significant number of deaths caused by bee stings. The Apidae family’s stingers are barbed, often getting stuck in the skin after a sting and can only be used for a single sting.
Then there’s the Vespidae family – wasps, yellow jackets, hornets – they are generally more aggressive than honeybees. These insects are present all over the U.S. Some wasps like to be alone and others live in groups. Social wasps, for instance, yellow jackets or hornets, tend to build large nests underground or in bushes or trees. Solitary wasps, like mud wasps, usually create smaller nests in place like window sides. Unlike bees, wasps from the Vespidae family don’t have barbed stingers, which means they can sting more than once.
Lastly, the Formicidae family, which includes all ants. Most ants use their pincer-shaped mouthparts, also known as mandibles, to bite; but some ants, much like bees and wasps, have developed the ability to sting with their abdomens. Fire ants, are an aggressive type that latch onto their target with their mandibles and then use their stinger to deliver multiple doses of venom. Fire ant colonies are often found in the Southeastern United States but are spreading rapidly to nearby areas. There are other species in the Formicidae family that can sting, but they are not found in the U.S., so we won’t talk about them here.
It’s essential to note that bee venom has some uses in apitherapy, a type of therapy that uses bee products for health benefits. However, when bee venom is applied to the eye or skin, it can sometimes cause severe allergic reactions or anaphylactic shock, which is a serious life-threatening allergic reaction.
Risk Factors and Frequency for Hymenoptera Stings
Stings from Hymenoptera insects, such as hornets and yellow jackets, can happen to anyone, regardless of their age or gender. These stings usually occur when someone accidentally disturbs an insect or their nest, resulting in one or multiple stings. People in certain jobs like construction, landscaping, or pest control are more likely to encounter these insects and get stung. Typically, the sting result in a small, temporary inflammation that disappears in a few days. However, at times, the reaction can be larger, more painful, and may last longer, requiring medical intervention. These severe reactions are rare. Even rarer are systemic reactions, which can be life-threatening.
- Stings from Hymenoptera insects happen to people of all ages and genders.
- These stings usually occur when an insect or their nest is accidentally disturbed.
- People working in fields like construction, landscaping, or pest control are more likely to get stung.
- Most stings result in small, temporary inflammation that goes away after a few days.
- Sometimes, the sting can cause a larger, more painful reaction that lasts longer and may need medical treatment.
- In rare cases, stings can lead to severe, life-threatening reactions.
- Every year, around 62 deaths in the US are linked to bites from these insects.
- While stings are common in children, adults who explore the jungle or hike in forests also frequently encounter these insects.
Signs and Symptoms of Hymenoptera Stings
Hymenoptera stings are usually identifiable upon inspection and by patient history. Patients who’ve been stung often report pain and swelling. Stings from the Apidae and Vespidae families (such as bees and wasps) cause almost immediate discomfort. Once stung, the patient may feel symptoms including pain, swelling, itching, and in some cases, bleeding within minutes. These symptoms may last for several hours. A physical examination may reveal redness, swelling, hardness, and warmth in the affected area. In some cases, the stinger, which might still be attached to the venom sac, could be stuck in the skin. It’s important to scrape off the stinger gently with a flat object like a credit card instead of squeezing it out or using tweezers.
Stings from fire ants also cause immediate pain followed by an itching or burning sensation. This is often followed by a raised bump surrounded by redness. Patients can also develop a small, pus-filled blister within 24 hours. Most reactions to Hymenoptera stings are mild, causing minor inflammation that subsides within a few days. However, some reactions can be more severe, with symptoms worsening over 48 hours before finally clearing up within 7 to 10 days. This heightened reaction is thought to be due to an allergic response.
Systemic reactions to insect stings are more serious. These reactions resemble severe allergic reactions (anaphylaxis), are quick to develop, and can be life-threatening. Patients with a history of anaphylaxis or previous severe allergic reactions to insect stings are particularly at risk. Symptoms can worsen rapidly and may include widespread hives, swelling, flushing, breathing difficulties, wheezing, and in severe cases, shock due to low blood pressure.
Testing for Hymenoptera Stings
The first thing that doctors typically check in medical situations are your airway, breathing, and circulation. This is commonly shortened to ‘ABC’.
If you’ve had a reaction to something, there are different types. Uncomplicated local reactions are generally mild and happen in a specific area. Symptoms might include swelling, hardened skin, warmth, and tenderness around the area of the reaction.
If that reaction happens over a wide area — larger than 10-cm — it’s called a large local reaction. Symptoms are generally the same as an uncomplicated local reaction, but they are more severe and last longer.
In some cases, the reaction might be systemic, which means it affects the whole body. This is often called anaphylaxis and can be dangerous. Symptoms can include a skin condition called ‘urticaria’, which you might know as hives; swelling in the face (angioedema); difficulty breathing due to narrowed airways (stridor); wheezing because of a spasm in the tubes that carry air to your lungs (bronchospasm); belly pain; feeling sick; being sick; and flushing (warmth and redness in your skin).
Treatment Options for Hymenoptera Stings
If you’ve been stung and only have a small area of swelling and pain, that’s called an uncomplicated reaction. Treat it by placing an ice pack on the area and taking over-the-counter pain relief like aspirin or Tylenol. It’s best to scrape out the stinger with something like a credit card as quickly as you can. Try not to squeeze or tweeze it out, as that can cause more venom to get into your skin.
If the swelling is more significant, the reaction is considered large. This kind of reaction can still be managed with the measures above, but you might also need a short course of a medication called a glucocorticoid. When taken for a few days, these medications can help to reduce swelling and improve symptoms by manipulating your body’s inflammatory response.
On rare occasions, a sting may cause a severe, whole-body reaction known as anaphylaxis. This is a medical emergency and needs immediate attention. First and foremost, an airway needs to be established because anaphylaxis can cause swelling to block air from entering the lungs. Healthcare professionals might achieve this by placing a tube into your windpipe. Alongside this, medications such as epinephrine, corticosteroids, and H1 and H2 antagonists will be administered, often directly into your bloodstream, to rapidly manage your body’s reaction to the venom. Epinephrine helps to open up your airways and increase your heart’s function, while corticosteroids and H1 and H2 antagonists act to decrease the immune system’s response and the resulting discomfort.
If you have any doubt about the severity of your reaction, it’s crucial to get medical attention right away in order to get the right treatment.
What else can Hymenoptera Stings be?
The following are medical conditions that can be mistaken for each other due to similar symptoms:
- An allergic reaction severe enough to cause anaphylaxis
- Bites from other insects
- Cellulitis, a skin infection
- Abscess, a pocket of pus
- Folliculitis, an infection of hair follicles
What to expect with Hymenoptera Stings
The outlook for most people stung by Hymenoptera insects, a group including bees and wasps, is generally positive. Typically, patients experience discomfort that lasts from a few minutes to a couple of days. However, if someone has a severe, systemic reaction to the sting, which means that the entire body is affected, it can be life-threatening if it’s not treated immediately. People who know that they have severe reactions to insect bites should avoid bees, wasps, and similar insects as much as possible, and they should also carry an epinephrine auto-injecting pen with them at all times. This pen can deliver a dose of medication that counteracts the reaction to the sting. It’s worth noting that approximately 62 people die each year in the United States due to bee and wasp stings.
Possible Complications When Diagnosed with Hymenoptera Stings
Following a sting from a fire ant, the most frequently seen issue is an infection. Fire ants tend to sting multiple times, which can cause sores than can turn into ulcers. Additionally, some patients who are given antihistamines – medicines often used to treat allergic reactions – have experienced rebound anaphylaxis, which is a potentially severe allergic reaction. The signs of an illness similar to serum sickness can show up about a week to two weeks after the sting. Other possible complications consist of kidney failure, rhabdomyolysis (a condition that can lead to kidney damage), swelling in the brain, and heart attack.
Possible Complications:
- Infection
- Multiple stibings leading to ulcers
- Rebound anaphylaxis with antihistamines
- Serum sickness-like reactions 7-14 days post sting
- Kidney failure
- Rhabdomyolysis
- Cerebral edema (brain swelling)
- Myocardial Infarction (heart attack)
