Derm Bug Bites

Black Widow bite

Brown Recluse bite 

  • Treatment:
    • Supportive debridement and topical ABX 
      • Cleansing the bite site,
      • rest, avoidance of exercise
      • Application of cool compresses, avoid warm compresses
      • Antibiotics to reduce secondary infection at the wound site
    • Acute phase:
      • +dexamethasone 
    • Loxosceles antivenoms
      • have been developed and are frequently used in South America, there is little evidence to support their effectiveness
    • Hyperbaric oxygen, dapsone intralesional and systemic corticosteroids, colchicine, and diphenhydramine.
    • Necrotic wounds heal slowly, may require surgical excision and reconstruction to close the resulting defect.
    • Surgical interventions should be delayed until the wound has stabilized.


  • Treatment:
    • Isolate bedding and clothes for 14 days >> heat treat
    • Topical treatment – permethrin 5%
      • Applied from the neck down, covering all surfaces of the skin including skin folds, under nails, between buttocks, belly button, toe creases, etc. Leave on overnight
      • Repeat treatment in 7 days
    • Oral treatment – Ivermectin
      • dosage of 200 µg/kg given twice 1 week apart.
      • Off label but commonly used
  • Prevention:
    • Family members / close contacts should be treated at the same time
    • Wash all bedding, pillows, worn clothing, etc in hot water and dry on high heat, the morning after tx