What is the treatment for a wasp sting?

Wasp Sting Treatment

For uncomplicated local reactions, immediately remove any visible stinger by scraping or plucking (speed matters more than method), then apply cold compresses, oral antihistamines, and topical corticosteroids to the sting site, with oral acetaminophen or ibuprofen for pain relief. 1

Immediate Stinger Management

• Remove the stinger within 60 seconds if visible by scraping with a fingernail or plucking it out—venom delivery continues for up to 60 seconds, and the method of removal doesn't matter, only speed does 1, 2
• Wash the area with soap and water after stinger removal 1
• Note that wasps typically do not leave stingers (unlike honeybees), but ground-nesting yellow jackets occasionally can 3

Treatment Algorithm by Reaction Severity

Local Reactions (Most Common Presentation)

• Apply cold compresses or ice packs to reduce pain and swelling 1, 4
• Administer oral antihistamines (e.g., diphenhydramine, cetirizine) to reduce itching 1
• Apply topical corticosteroids directly to the sting site for local inflammation and itching 1, 5
• Give oral acetaminophen or ibuprofen for pain relief 1, 5
• Do NOT prescribe antibiotics—the swelling is allergic inflammation, not infection 1, 2, 5

This conservative approach is effective for the majority of wasp stings, which are self-limiting and resolve within hours to a few days 3, 4.

Large Local Reactions (Swelling >5-8 cm, Lasting >1 Week)

• Initiate a short course of oral corticosteroids promptly (within the first 24-48 hours) to limit progression of extensive swelling 1, 5
• Continue cold compresses and oral antihistamines as adjunctive therapy 1
• These reactions are IgE-mediated late-phase responses that peak at 48-72 hours and can last over a week 3
• The risk of systemic anaphylaxis in future stings for patients with only large local reactions is low, so venom immunotherapy is generally not necessary unless there is frequent unavoidable exposure 3

Anaphylaxis (Life-Threatening Emergency)

This is the most critical scenario requiring immediate recognition and treatment:

• Immediately administer intramuscular epinephrine 0.01 mg/kg (up to 0.3 mg) in children or 0.3-0.5 mg in adults into the anterolateral thigh 1, 2, 6
• Epinephrine is the ONLY first-line treatment for anaphylaxis—antihistamines and corticosteroids are NOT substitutes and play no role in acute management 1, 5
• Activate emergency medical services immediately 1
• Be prepared to repeat epinephrine dosing every 5-15 minutes if symptoms persist or recur 1
• Position the patient supine with legs elevated (if tolerated) to maintain blood pressure 6

Signs of anaphylaxis include: hypotension, loss of consciousness, shock, airway compromise, laryngeal edema (the most common cause of death from wasp sting anaphylaxis), bronchospasm, stridor, wheezing, widespread urticaria, angioedema, or gastrointestinal symptoms 3, 2, 6, 7.

Delayed epinephrine administration is associated with fatal outcomes—prompt use within minutes is critical 1. Laryngeal edema can progress rapidly and cause death 3, 2.

Critical Pitfalls to Avoid

• Never delay epinephrine in anaphylaxis to give antihistamines or corticosteroids first—this can be fatal 1, 5
• Don't prescribe antibiotics for swelling—this is allergic inflammation, not bacterial infection 1, 2, 5
• Don't waste time trying to identify the specific insect—treat based on clinical presentation 1
• Any sting to the eye itself (not eyelid) requires immediate ophthalmologic evaluation due to risk of permanent vision loss 1
• Don't assume a single sting is safe—anaphylactic reactions are not dose-dependent and can occur from a single sting 4

Post-Treatment Management

For All Patients with Systemic Reactions:

• Prescribe an epinephrine autoinjector (e.g., EpiPen, Auvi-Q) and provide training on self-administration 3, 1, 2
• Refer to an allergist-immunologist for venom-specific IgE testing (skin testing or serum IgE) 3, 1, 2
• Consider venom immunotherapy (VIT) for patients with confirmed venom-specific IgE and history of systemic reactions—VIT reduces the risk of future systemic reactions from 25-70% down to approximately 5% 3, 8
• Warn patients about possible recurrence of symptoms and instruct them to seek medical attention if symptoms return 6

Special Considerations:

• Children ≤16 years with only cutaneous systemic reactions (generalized hives without respiratory or cardiovascular symptoms) generally do not require VIT 3
• Adults with only cutaneous manifestations are generally considered candidates for VIT, though this remains somewhat controversial 3
• Patients with mastocytosis or elevated baseline serum tryptase are at higher risk for severe reactions and should have the greatest benefit from VIT 3, 7
• Multiple stings (typically >100) can cause toxic reactions from massive envenomation even in non-allergic individuals, with an estimated lethal dose of approximately 20 stings/kg 1, 4, 9

Venom Immunotherapy Efficacy:

VIT is highly effective, with only 2.7% of treated patients experiencing systemic reactions to subsequent stings compared to 39.8% of untreated patients 8. However, VIT itself carries a 9-14% risk of systemic adverse reactions during treatment, with bee venom VIT having higher rates than wasp venom VIT 8.

Monitoring and Follow-Up

• Observe all patients with stings for at least 30-60 minutes for signs of delayed anaphylaxis 4
• Patients with diabetes should monitor blood glucose following epinephrine administration, as levels may increase 6
• Watch for rare complications including acute kidney injury, hepatitis, rhabdomyolysis, hemolysis, and thrombocytopenia, particularly after multiple stings 9
• Monitor injection sites for signs of infection (persistent redness, warmth, swelling, tenderness), as rare cases of necrotizing fasciitis have been reported after epinephrine injection 6