Most people experience only a temporary, localized reaction to a bee sting. A bee sting introduces venom, a complex mixture of proteins and small molecules, causing immediate pain and inflammation. The term “bee allergy” often includes all stinging insects of the Hymenoptera order, such as wasps and hornets. Understanding the difference between a normal reaction and a true, life-threatening allergy is the first step in managing a sting incident.
Normal Reactions Versus Allergic Responses
When most people are stung, the body reacts with a predictable local response that is not a true allergy. This normal reaction involves immediate, sharp pain, redness, and a small welt at the sting site. The localized swelling typically remains small and resolves entirely within a few hours to a day.
A more pronounced but still non-allergic response is known as a large local reaction. Swelling intensifies over one to two days and can reach ten centimeters or more in diameter, persisting for up to a week. However, these symptoms remain confined to the sting area and are not considered systemic.
In contrast, a true allergic response, or anaphylaxis, is a systemic reaction that occurs away from the sting site and requires immediate medical attention. Symptoms develop rapidly, often within minutes, and can include generalized hives, itching, or flushing. More concerning signs involve the respiratory and circulatory systems, such as difficulty breathing, throat swelling, dizziness, or a sudden drop in blood pressure. This systemic reaction is potentially life-threatening, and a history of an allergic reaction signals the need for expert evaluation and preparedness.
What Triggers a Severe Bee Sting Allergy
A severe bee sting allergy is triggered by an acquired immune response to proteins found within the venom. Phospholipase A2 (PLA2) is the major allergen in honeybee venom, which the immune system mistakenly identifies as a threat after an initial sensitizing exposure.
Upon sensitization, the body produces Immunoglobulin E (IgE) antibodies designed to target the venom components. These IgE antibodies attach to the surface of mast cells and basophils, priming the immune system for a future encounter.
When the person is stung again, the venom proteins cross-link the IgE antibodies on these immune cells. This signals the cells to rapidly release chemical mediators, including histamine, into the bloodstream. This sudden release causes the systemic symptoms of anaphylaxis, such as airway constriction and low blood pressure.
Diagnosis and Management of Venom Hypersensitivity
Diagnosis of Venom Hypersensitivity
Diagnosis of venom hypersensitivity is confirmed through specific clinical testing for individuals who have experienced a systemic reaction. Blood tests measure the quantity of venom-specific IgE antibodies in the serum. Skin prick tests and intradermal skin tests are also employed, introducing tiny amounts of venom extract into the skin to observe a localized allergic reaction.
An elevated baseline serum tryptase level may also be measured, as this enzyme is released by mast cells and indicates a risk factor for more severe sting reactions. These procedures help the clinician confirm the specific insect responsible for the allergy and assess the severity of the patient’s sensitivity.
Immediate Management
Immediate management for a systemic reaction involves carrying and promptly administering an epinephrine auto-injector. Epinephrine acts quickly to relax airway muscles, tighten blood vessels to raise blood pressure, and reverse swelling, directly counteracting the effects of chemical mediators. This medication is the first-line treatment for anaphylaxis and must be used at the first sign of a severe reaction.
Long-Term Prevention
For long-term, preventative management, Venom Immunotherapy (VIT) is the most effective treatment for reducing the risk of future severe reactions. VIT involves the subcutaneous injection of gradually increasing doses of the specific venom. This process desensitizes the immune system, leading to the production of protective IgG antibodies that block the allergic IgE response. VIT is highly effective, with success rates reported to be around 80% for bee venom, and is recommended for patients who have had a clear systemic reaction.