What is the recommended management of a wasp sting?

Wasp Sting Management

For most wasp stings, treatment is symptomatic only: apply cold compresses, use oral antihistamines for itching, and oral analgesics for pain—no specific medical intervention is required. 1

Immediate Assessment: Local vs. Systemic Reaction

First, determine the type of reaction:

Local Reactions (Most Common)

• Redness, swelling, itching, and pain at the sting site
• No treatment usually required for mild reactions 1

Large Local Reactions

• Swelling >10 cm in diameter contiguous to sting site
• Increases in size over 24-48 hours
• Takes 5-10 days to resolve 1

Systemic Reactions (Life-Threatening)

• Manifestations NOT contiguous with sting site:
  • Urticaria/angioedema away from sting
  • Bronchospasm or upper airway obstruction
  • Hypotension/shock
  • GI symptoms (nausea, vomiting, diarrhea)
  • Neurological symptoms 1

Treatment Algorithm

For Simple Local Reactions

• Cold compresses to reduce pain and swelling
• Oral antihistamines for itching
• Oral analgesics for pain
• Antibiotics are NOT indicated unless secondary infection develops (a commonly misdiagnosed scenario—the swelling is from mediator release, not infection) 1

For Large Local Reactions

• Cold compresses
• Oral antihistamines
• Oral analgesics
• Consider a short course of oral corticosteroids for severe cases, though controlled trial evidence is lacking 1
• Swelling occurs in first 24-48 hours due to allergic inflammation, not infection
• Do not prescribe antibiotics unless clear evidence of secondary infection 1

Important caveat: Topical aspirin paste is NOT effective and actually increases duration of redness—avoid this outdated recommendation 2

For Systemic Reactions (EMERGENCY)

This is anaphylaxis—treat immediately:

1. Administer epinephrine intramuscularly in the anterolateral thigh (0.01 mg/kg, up to 0.3 mg in children; 0.3-0.5 mg in adults) 1

   • IM injection in thigh achieves faster, higher plasma concentration than subcutaneous or arm injection
   • Delayed epinephrine administration is associated with fatal outcomes 1
   • May require repeat dosing for persistent symptoms
   • No contraindication to epinephrine in life-threatening anaphylaxis, even with cardiovascular disease or β-blockers 1

2. Provide supportive therapy

3. Transport to emergency department 1

Post-Sting Management for At-Risk Patients

Who Needs Further Evaluation?

Refer to allergist-immunologist if patient had:

• Any systemic reaction (25-70% risk of future anaphylaxis without treatment) 1
• Severe large local reactions with frequent unavoidable exposure 1

Long-Term Prevention for Systemic Reactors

Patients with history of systemic reactions should:

1. Carry injectable epinephrine at all times and know how to use it 1

   • Consider prescribing >1 autoinjector (some patients need multiple doses) 1

2. Undergo venom-specific IgE testing (skin testing preferred initially) 1

3. Consider venom immunotherapy (VIT), which reduces future reaction risk from 25-70% to nearly zero 1

   • Typically continued for 5 years
   • May need indefinite therapy if history of severe anaphylaxis with shock/loss of consciousness 1

4. Implement avoidance measures:

   • Remove nests near home by professionals
   • Avoid bright colors, flowery prints, strong scents
   • Wear protective clothing outdoors
   • Avoid walking barefoot
   • Be cautious near garbage, picnic areas 1

Common Pitfalls to Avoid

• Don't prescribe antibiotics for large local reactions—the swelling is allergic inflammation, not infection 1
• Don't delay epinephrine in systemic reactions—this is the leading cause of fatal outcomes 1
• Don't use topical aspirin—it's ineffective and prolongs redness 2
• Don't assume patients with only large local reactions need VIT—most need only symptomatic care, though optional epinephrine prescription is reasonable 1
• Don't withhold epinephrine due to cardiovascular disease or β-blockers—there is no contraindication in anaphylaxis 1

Special Consideration: Stinger Removal

If a barbed stinger is present (honeybees, not wasps), remove within 10-20 seconds by flicking/scraping with fingernail. Don't grasp the venom sac—this injects additional venom 1