Black widow (Latrodectus) bite: identify the incorrect statement
E) Hospitalization is not required — is NOT correct. Systemic neurotoxic effects (severe crampy pain, muscle rigidity, hypertension, diaphoresis) can be serious and warrant medical evaluation and often observation/admission, especially with severe pain, muscle rigidity, or systemic signs to prevent morbidity and mortality 1.
Evidence-based framing (most recent, highest quality):
- Black widow bites are neurotoxic, causing severe crampy pain, muscle rigidity, diaphoresis, and hypertension; importantly, they do not cause local tissue necrosis (distinguishes from brown recluse) 1.
- Guidelines direct seeking urgent care/hospital-level evaluation for systemic symptoms (eg, muscle rigidity, breathing difficulty, confusion, severe pain beyond the bite), contradicting the blanket statement that “hospitalization is not required” 1.
- Large U.S. poison center review: most cases are minor, but 10% required hospital admission; antivenom used infrequently; supportive care common — reinforcing that admission is sometimes necessary for safety and symptom control 2.
Appraise each option:
- A) “Over 4 cm, black, orange spot on abdomen” — Acceptable: female Latrodectus are black with a characteristic red/orange hourglass/spot on ventral abdomen; body plus leg span can exceed 4 cm 1.
- B) “Transient pain and local necrosis; patient may initially ignore it” — Partly correct/nuanced: initial pain can be mild and ignored, but necrosis is incorrect for black widow (no local tissue injury) 1. However, within the set, E is more clearly incorrect with respect to clinical management and outcomes.
- C) “Neurotoxic; severe abdominal muscle spasms mimicking acute abdomen/peritonitis” — Correct; classic “washboard abdomen” and autonomic findings are well-described 1, 3, 4.
- D) “Symptoms subside within 48 hours” — Often true; many resolve in 1–3 days with supportive care, though severe cases can last longer or complicate (eg, rhabdomyolysis) 2, 3.
- E) “Hospitalization is not required” — Incorrect; systemic cases require ED evaluation and may need admission for analgesia, benzodiazepines, monitoring, and occasionally antivenom to reduce morbidity and protect quality of life 1, 2.
Action algorithm (to minimize morbidity/mortality/QoL loss):
- Suspect Latrodectus with severe crampy pain, rigid “board-like” abdomen, diaphoresis, hypertension, minimal local skin findings 1.
- Immediate ED referral if systemic symptoms or severe pain; consider admission if uncontrolled pain/rigidity, autonomic instability, extremes of age, comorbidities, or complications (rhabdomyolysis, renal issues, respiratory compromise) 1, 2.
- Supportive care first; antivenom reserved for severe, refractory symptoms in consultation with toxicology to expedite recovery and reduce suffering 2.
Pitfalls to avoid: