From the Guidelines
The most effective treatment for a Hymenoptera sting that causes a severe allergic reaction is the immediate use of epinephrine via an auto-injector like an EpiPen, as recommended by the 2024 American Heart Association and American Red Cross guidelines for first aid 1.
Key Recommendations
- For a severe reaction, inject the EpiPen into the outer thigh muscle through clothing if necessary, holding it in place for 3 seconds.
- After administration, call emergency services immediately as the effects of epinephrine are temporary, lasting only 10-20 minutes.
- While waiting for help, the person should lie flat with legs elevated unless they have difficulty breathing, in which case they should sit up.
Additional Treatments
- Antihistamines like diphenhydramine (Benadryl) at 25-50mg orally or H2 blockers like ranitidine may be used as additional treatments, though they should not replace epinephrine.
- For mild local reactions without systemic symptoms, remove the stinger if visible by scraping it away (don't squeeze), clean the area, apply ice to reduce swelling, and take oral antihistamines and pain relievers as needed, as suggested by the guidelines 1.
Important Considerations
- Epinephrine is the drug of choice for the treatment of anaphylaxis, and its use is not contraindicated in patients with cardiovascular disease, as the risk of a life-threatening anaphylactic reaction exceeds the risk of administering epinephrine 1.
- Patients allergic to insect venom should carry epinephrine at an appropriate dosage for administration in case of a sting, and should be taught how to administer it and under what circumstances to do so 1.
From the Research
Treatment for Hymenoptera Sting
- The treatment for a Hymenoptera sting, such as an EpiPen, depends on the severity of the reaction 2, 3, 4.
- For mild reactions, symptomatic therapy may be sufficient, while more severe reactions may require specific diagnosis or allergen immunotherapy (AIT) with Hymenoptera venom (VIT) 2.
- In cases of anaphylaxis, prompt recognition and treatment with epinephrine, such as an EpiPen, is crucial 3, 4, 5.
- Venom immunotherapy (VIT) is a long-term treatment that can help reduce the risk of future allergic reactions and improve quality of life 2, 6.
- The standard maintenance dose of VIT is 100 µg Hymenoptera venom, and it is typically administered at 4-weekly intervals during the first year and every 5-6 weeks from the second year onwards 2.
Diagnosis and Risk Factors
- Diagnosis of Hymenoptera venom allergy involves determining concentrations of specific IgE antibodies to bee and/or vespid venoms, their constituents, and other venoms as appropriate 2.
- Risk factors for more severe reactions include mast cell disease, uncontrolled asthma, and a history of previous anaphylactic reactions 2, 4.
- Patients with a history of severe reactions or additional risk factors may require more intensive treatment, such as a higher dose of VIT or co-medication with an anti-IgE antibody 2.
Management and Prognosis
- Management of Hymenoptera sting hypersensitivity involves a combination of prophylaxis, patient self-treatment measures, and VIT 2, 3, 4.
- The prognosis for patients with Hymenoptera venom allergy is generally good, with most patients experiencing a significant reduction in symptoms and improved quality of life with treatment 2, 6.
- However, some patients may require long-term treatment, and in rare cases, anaphylaxis can be life-threatening 3, 5.