Spider bite

 
  • Black Widow
    • Morphology
      • Black with a red hourglass on the belly
      • Female is bigger than male. She kills the male after copulation
        • notion image
    • Mechanism
      • Most potent neurotoxin in the world, but spider is small, a single bite won’t kill you (5-6 bites)
    • Clinical presentation:
      • Bitten patients experience nausea, vomiting, and severe generalized muscle cramps.
    • Treatment
      • The antidote is IV calcium gluconate.
      • Muscle relaxants also help.
  • Brown recluse spider (aranha violino)
    • Morfologia
      • Mancha em forma de violino no cefalotórax
      • Pertence ao género Loxosceles
        • notion image
    • Mechanism
      • Toxin is “Dermatolysin” → causes necrosis of the skin
    • Clinical presentation
      • Bites are often not recognized at the time of the bite.
      • In the next several days, a skin ulcer develops, with a necrotic center and a surrounding halo of erythema.
      • Necrotic ulcer in evolution for up to 10 days
    • Treatment
      • Dapsone is helpful if too much invenomnaton with systemic effects
      • Surgical debridement of all necrotic tissue is needed.
      • Skin grafting may be needed subsequently.