What is the treatment for insect bites?

Treatment for Insect Bites

For most insect bites, treatment should include cleaning the wound with soap and water, applying cold compresses, and using over-the-counter antihistamines and topical corticosteroids for symptom relief. 1

Initial Management

1. Immediate care:

   • Remove any stinger as quickly as possible (particularly important for honeybee stings) 1
   • Thoroughly clean the wound with soap and water 1
   • Apply ice or cold packs to the bite site (with a thin barrier between ice and skin) to reduce pain and swelling 1

2. Symptomatic relief:

   • For itching: Use oral antihistamines and topical corticosteroids such as hydrocortisone 2
   • For pain: Use over-the-counter pain medications like acetaminophen or NSAIDs (ibuprofen) 1
   • For swelling: Elevate the affected limb if significant swelling is present 1

Treatment Based on Reaction Severity

Mild Local Reactions

• Continue H1 antihistamines (e.g., diphenhydramine 25-50 mg every 6 hours) 1
• Consider adding H2 antihistamines (e.g., ranitidine 150 mg twice daily) 1
• Apply topical hydrocortisone to relieve itching 2
• Monitor for 48-72 hours for signs of infection 1

Large Local Reactions

• These reactions extend more than 10 cm in diameter and may take 5-10 days to resolve 1
• Treatment includes:
  • Oral antihistamines
  • Consider oral corticosteroids (prednisone 40-60 mg daily for 2-3 days) 1
  • Cold compresses
  • Elevation of affected limb if swelling is significant

Severe Reactions/Anaphylaxis

• Administer epinephrine 0.3-0.5 mg IM in the anterolateral thigh immediately 1, 3
• Place patient on cardiac monitor and establish IV access 1
• Antihistamines and corticosteroids can be used as secondary treatments but are not substitutes for epinephrine 1
• Observe patients for at least 4-6 hours after treatment 1
• Prescribe epinephrine auto-injector (2 doses) if any systemic symptoms develop 1

Special Considerations

Signs of Infection

• If signs of infection develop (increasing redness, warmth, swelling, pain, or purulent drainage):
  • Consider antibiotic therapy, options include: 1
    • Amoxicillin-clavulanate 875/125 mg twice daily
    • Cephalexin 250-500 mg four times daily
    • Clindamycin 300-400 mg three times daily (for penicillin-allergic patients)
    • Doxycycline 100 mg twice daily (particularly for Pasteurella species)

High-Risk Situations Requiring Immediate Medical Attention

• Multiple stings (especially >10)
• Signs of infection
• History of severe allergic reactions to insect stings
• Stings inside the mouth or throat
• Signs of systemic reaction (difficulty breathing, widespread hives, dizziness)
• Stings to the eye 1

Prevention Strategies

• Wear protective clothing (long sleeves and pants) during outdoor activities 1
• Avoid bright colors and strong scents that attract insects 1
• Use DEET-containing insect repellents (10-30%) 1
• Remove nests and avoid areas with standing water 1
• Use screens on windows and doors 1

Common Pitfalls to Avoid

1. Overuse of antibiotics: Recent research shows that antibiotics are likely overused for insect bites, with nearly three-quarters of patients receiving prescriptions despite limited evidence of bacterial infection 4. Reserve antibiotics for clear signs of infection.

2. Neglecting antihistamines: Only 22% of patients with insect bites were taking antihistamines before consulting despite 45% complaining of itch 4. Encourage early use of antihistamines for symptomatic relief.

3. Mistaking insect bite inflammation for cellulitis: Insect bite inflammation can mimic cellulitis, leading to unnecessary antibiotic use 4. Look for systemic symptoms and progression beyond expected reaction to differentiate.

4. Delaying epinephrine in anaphylaxis: For severe allergic reactions, epinephrine is the first-line treatment and should not be delayed or substituted with antihistamines or corticosteroids alone 1, 3.

5. Inadequate follow-up: Monitor the bite site for 48-72 hours for signs of infection progression, and consider follow-up within 24-48 hours to assess response to treatment 1.