Black Widow Spider Bite: Symptoms, Treatment & Myths

Latrodectus mactans (Southern black widow) venom = α-latrotoxin → massive neurotransmitter release (ACh, NE, dopamine). Deaths extremely rare (none in healthy US adults since 1983).

Symptom Spectrum

Grade	Features	Management
Mild (local)	Pinprick pain, erythema, diaphoresis at site	Ice, analgesia, observe
Moderate (systemic)	Muscle pain/cramping (abdomen, back, thighs), tremor, nausea, hypertension, tachycardia, headache	IV benzodiazepines (diazepam 2–10 mg) for muscle spasms; opioids if severe pain; hydration
Severe	Respiratory distress, priapism, seizures, altered mental status, rhabdomyolysis	ICU, antivenom (Analatro), aggressive supportive care

Antivenom (Analatro / Antivenin Latrodectus mactans)

• Indications: Severe systemic toxicity, pregnancy, extremes of age, comorbid CVD, failure of benzodiazepines/opioids.
• Dose: 1 vial (6,000 units) IV over 30 min; may repeat.
• Risk: Serum sickness (delayed), anaphylaxis (rare). Skin test not predictive.

Prevention

• Gloves + long sleeves for woodpiles, clutter, outbuildings.
• Shake out shoes/clothing stored in garage/shed.
• Seal cracks, reduce clutter, outdoor lighting (attracts prey).

Myth Busting

• "Always fatal" — false.
• "Must identify spider" — clinical diagnosis sufficient.
• "Apply tourniquet / cut / suck venom" — harmful; don't do.