How to treat bug bites?

Treatment of Bug Bites

For most insect bites and stings, symptomatic treatment with cold compresses, oral antihistamines, and topical corticosteroids is sufficient and effective. 1

Types of Bug Bite Reactions

Local Reactions

• Mild local reactions (most common):

  • Redness
  • Swelling
  • Itching and pain
  • Usually resolve within hours to days

• Large local reactions:

  • Increase in size for 24-48 hours
  • Swelling extending >10 cm in diameter around the bite site
  • Take 5-10 days to resolve
  • Usually IgE-mediated but self-limited

Systemic Reactions

• Range from mild to life-threatening:
  • Cutaneous (urticaria, angioedema)
  • Respiratory (bronchospasm, upper airway obstruction)
  • Cardiovascular (arrhythmias, hypotension, shock)
  • Gastrointestinal (nausea, vomiting, diarrhea)
  • Neurological (seizures)

Treatment Algorithm

1. For Mild Local Reactions

• Cold compresses to reduce pain and swelling 1
• Oral antihistamines to reduce itching 1
• Topical hydrocortisone applied to affected area up to 3-4 times daily 2
• Oral analgesics if needed for pain 1

2. For Large Local Reactions

• All treatments for mild reactions PLUS:
• Oral corticosteroids for severe cases (short course) 1
• Important note: Antibiotics are NOT indicated unless there is evidence of secondary infection 1

3. For Systemic Reactions

• Epinephrine is the drug of choice for anaphylaxis 1
  • 0.01 mg/kg in children (up to 0.3 mg)
  • 0.3-0.5 mg in adults depending on severity
  • Intramuscular injection in anterolateral thigh preferred
  • No contraindication to epinephrine use in life-threatening situations, even with cardiovascular disease 1
• Supportive care and transport to emergency department 1

Special Considerations

Fire Ant Stings

• Typically cause sterile pseudopustules within 24 hours
• Keep vesicles intact and clean to prevent secondary infection 1

Stinging Insect Identification

• Identifying the insect can help with diagnosis and treatment
• Consider:
  • Activity at time of sting (e.g., yard work)
  • Location (near eaves, garbage cans)
  • Visual identification of insect
  • Time of year
  • Geographic location 1

Prevention for Future Bites

• Avoidance measures:
  • Remove known nests near home
  • Avoid bright clothing or flowery prints
  • Avoid strong scents that attract insects
  • Wear protective clothing outdoors
  • Be cautious near bushes, garbage containers, and picnic areas 1

Common Pitfalls to Avoid

1. Misdiagnosing large local reactions as infections

   • Swelling and redness from insect bites are typically due to allergic inflammation, not infection
   • Antibiotics are unnecessary unless there are clear signs of secondary infection 1

2. Delaying epinephrine in anaphylaxis

   • Fatal outcomes are associated with delay or lack of epinephrine administration
   • Antihistamines and corticosteroids are not substitutes for epinephrine in anaphylaxis 1

3. Removing stingers incorrectly

   • If a barbed stinger is present (e.g., from honeybees), remove it within 10-20 seconds
   • Flick or scrape away with fingernail rather than grasping, which can inject more venom 1

For patients with history of severe systemic reactions to insect stings, referral to an allergist-immunologist is recommended for consideration of venom immunotherapy to prevent future severe reactions 1.