What is the treatment for a caterpillar sting or bite?

Treatment for Caterpillar Stings/Bites

The primary treatment for caterpillar stings includes immediate removal of implanted spines with adhesive tape, followed by washing the area with soap and water, applying cold compresses, and managing symptoms with oral antihistamines, analgesics, and topical steroids. 1, 2

Initial Management

Immediate Steps

• Remove spines/hairs: Use adhesive tape (particularly silk tape) to extract embedded caterpillar spines from the skin 1
• Clean the area: Wash thoroughly with soap and water to prevent secondary infection 2
• Elevate the affected area: This helps reduce swelling and accelerates healing 2

Symptom Management

1. Pain control:

   • Apply cold compresses to reduce local pain and swelling 2
   • Use over-the-counter analgesics:
     • Acetaminophen or NSAIDs for pain relief 2
     • Topical lidocaine (if skin is intact) may help relieve local pain 2

2. Itching and inflammation:

   • Oral antihistamines to reduce itching 2
   • Topical corticosteroids for delayed hypersensitivity skin reactions 2

Monitoring and When to Seek Advanced Care

Watch for signs of:

• Systemic reactions: Nausea, vomiting, abdominal pain, headache 1
• Infection: Increasing redness, warmth, swelling, or purulent discharge 2
• Severe allergic reaction: Difficulty breathing, widespread hives, facial swelling 3

Seek immediate medical attention if:

• Symptoms worsen or persist beyond 48-72 hours 2
• Signs of systemic toxicity develop 2
• Severe allergic reaction occurs (anaphylaxis) 3

Special Considerations

Severe Reactions

• For severe allergic reactions, emergency treatment with epinephrine may be required 3
• Epinephrine is indicated for emergency treatment of allergic reactions including those from insect stings/bites that progress to anaphylaxis 3

Specific Caterpillar Species

• Asp caterpillar (Megalopyge opercularis) envenomations are particularly painful and may require more aggressive symptom management 1
• Saddleback caterpillar stings can cause significant local reactions and occasionally systemic symptoms 4
• Puss caterpillar stings have been associated with severe abdominal pain in some cases, which may respond to intravenous calcium gluconate 5

Prevention

• Wear long sleeves, long pants, and closed shoes when in areas where caterpillars may be present 2
• Avoid areas with high uncut grass, weeds, and low brush, especially during warm months 2
• Be cautious around trees and foliage where caterpillars typically inhabit 1

Most caterpillar stings cause self-limited symptoms that resolve with appropriate first aid and symptomatic care. However, monitoring for progression of symptoms is essential, as some species can cause more severe reactions requiring medical intervention.