Differential Diagnosis for Paresthesias Post Spider Bite

• Single Most Likely Diagnosis
  • Brown Recluse Spider Bite: This is a common cause of paresthesias after a spider bite, particularly in regions where the brown recluse spider is prevalent. The venom from the brown recluse spider can cause necrotic lesions and neurological symptoms, including paresthesias.
• Other Likely Diagnoses
  • Black Widow Spider Bite: The venom from a black widow spider bite can cause neurological symptoms, including paresthesias, along with severe pain, muscle cramps, and abdominal distress.
  • Hobo Spider Bite: Similar to the brown recluse spider, the hobo spider's venom can cause necrotic lesions and neurological symptoms, including paresthesias.
  • Tarantula Bite: While most tarantula bites are harmless, some species can cause paresthesias and other neurological symptoms due to the venom.
• Do Not Miss Diagnoses
  • Tetanus: Although rare, tetanus infection can occur through any wound, including a spider bite. It's crucial to ensure the patient's tetanus vaccination is up to date, as tetanus can be deadly if not treated promptly.
  • Gas Gangrene: This is a rare but potentially deadly infection that can occur if the spider bite becomes infected with Clostridium perfringens. It requires immediate medical attention.
• Rare Diagnoses
  • Lyme Disease: While not directly caused by a spider bite, ticks can sometimes be mistaken for spiders. If the patient has been in an area where Lyme disease is prevalent, it's essential to consider this diagnosis.
  • Other Venomous Spider Bites: Depending on the geographical location, other venomous spiders like the Sydney funnel-web spider or the redback spider could cause paresthesias, although these are less common in most areas.