A wasp sting results in immediate, sharp pain, followed by localized redness, swelling, and itching at the sting site. For most, these reactions are temporary and resolve within a few hours without complications. Wasp venom contains various compounds, including acetylcholine and serotonin, which contribute to the intense stinging sensation and localized inflammation.
Factors Influencing Sting Severity
While most wasp stings cause only minor discomfort, two scenarios can lead to a severe, potentially fatal outcome. Anaphylaxis, a severe systemic allergic reaction, occurs when the immune system overreacts to wasp venom. This reaction can rapidly cause widespread symptoms, including airway constriction, significant drops in blood pressure, and vascular collapse. Even a single sting can trigger anaphylaxis in sensitized individuals, with most severe reactions occurring within 10 to 30 minutes.
Alternatively, a large number of stings can lead to systemic toxicity, even in individuals without a pre-existing allergy. Wasp venom contains components that can directly damage various organs and tissues. A high venom load can overwhelm the body’s systems, leading to direct tissue and organ damage, including the kidneys, liver, heart, and nervous system. While the exact number varies, an average adult can withstand over 1,000 stings, but as few as 20 to 200 wasp stings can be life-threatening, particularly if they occur on the head or neck.
Signs of a Life-Threatening Reaction
Identifying the signs of a severe reaction is important for prompt action. Symptoms of anaphylaxis can include widespread hives, itching, or a rash that spreads beyond the sting site. Swelling of the face, lips, tongue, or throat can develop, potentially leading to difficulty breathing, wheezing, or a feeling of throat tightness. Other indications are dizziness, lightheadedness, a rapid or weak pulse, and a sudden drop in blood pressure, which can cause fainting or loss of consciousness. Nausea, vomiting, diarrhea, or abdominal cramping may also occur.
In cases of systemic toxicity from multiple stings, symptoms can reflect organ damage rather than an allergic response. These may include severe pain and muscle cramps, headache, or fever. Dark-colored urine, indicating kidney involvement, confusion, or seizures can also be present. While distinct, it is possible for both allergic and toxic reactions to occur simultaneously, though this is rare.
Emergency Response to a Severe Sting
Immediate action is necessary when a severe reaction occurs. Call emergency services without delay if someone shows signs of anaphylaxis or systemic toxicity. For individuals with a known wasp allergy, administer an epinephrine auto-injector (such as an EpiPen) into the mid-outer thigh at the first sign of a severe reaction. Epinephrine works by constricting blood vessels to raise blood pressure, relaxing airway muscles to improve breathing, and reducing swelling. Patients should carry two auto-injectors, as a second dose might be needed if symptoms persist.
Keep the person calm and have them lie face up and still, loosening any tight clothing. If they are struggling to breathe, raising their shoulders or having them sit up slowly can help. Monitor their breathing and consciousness until medical help arrives, and if vomiting occurs, turn them to their side to prevent choking. For mild, localized reactions, remove any visible stinger, wash the area with soap and water, and apply a cold compress to reduce swelling and pain.
Avoiding Wasp Stings
Preventing wasp stings involves several practical measures. When outdoors, avoid sudden movements near wasps, as this can provoke them. Wearing light-colored, loose-fitting clothing that covers exposed skin, such as long sleeves and pants, can offer some protection. Strong scents like perfumes, colognes, or lotions can attract wasps, so it is advisable to minimize their use when outdoors.
Exercise caution when consuming food or sugary drinks outside; keep food covered and avoid drinking directly from open cans, as wasps can crawl inside unnoticed. Promptly clean up any food spills. At home, seal cracks in foundations or walls to prevent wasps from entering. Regularly dispose of outdoor trash in sealed bins and inspect outdoor areas, like play equipment, before use. For large or aggressive wasp nests near living spaces, contacting professional pest control for removal is recommended.