When should a patient with suspected acute Lyme disease be referred to the emergency room (ER)?

When to Refer Suspected Acute Lyme Disease to the Emergency Room

Patients with suspected acute Lyme disease should be referred to the emergency room if they present with signs of cardiac involvement, neurological complications, or severe systemic illness that requires immediate intervention.

Cardiac Manifestations Requiring ER Referral

• Significant PR prolongation (PR >300 milliseconds) on ECG requires immediate hospital admission with continuous ECG monitoring 1
• Arrhythmias of any type associated with Lyme disease warrant emergency evaluation 1
• Clinical manifestations of myopericarditis including:
  • Exercise intolerance
  • Palpitations
  • Presyncope or syncope
  • Pericarditic pain
  • Evidence of pericardial effusion
  • Elevated cardiac biomarkers (such as troponin)
  • Edema
  • Shortness of breath 1

Neurological Manifestations Requiring ER Referral

• Meningitis with symptoms such as severe headache, neck stiffness, and photophobia 1, 2
• Encephalitis presenting with altered mental status, confusion, or seizures 1, 3
• Rapidly progressive peripheral neuropathy causing significant weakness or sensory deficits 3
• Severe radiculopathy causing significant pain or motor deficits 3

Other Indications for Emergency Evaluation

• Severe systemic illness with high fever, significant malaise, or signs of sepsis
• Inability to tolerate oral medications due to nausea, vomiting, or other reasons
• Immunocompromised patients with suspected Lyme disease and systemic symptoms
• Pregnant patients with acute Lyme disease and systemic symptoms

Clinical Assessment Algorithm

1. Evaluate for cardiac involvement:

   • Ask about chest pain, palpitations, lightheadedness, syncope, shortness of breath
   • Perform ECG if any cardiac symptoms are present
   • Refer to ER if PR interval >300ms or other significant arrhythmias are detected 1

2. Assess for neurological complications:

   • Check for headache, neck stiffness, altered mental status, focal neurological deficits
   • Evaluate for cranial nerve palsies (especially facial palsy)
   • Refer to ER if signs of meningitis, encephalitis, or severe radiculopathy are present 1, 3

3. Evaluate systemic illness severity:

   • Assess vital signs, particularly for fever, tachycardia, or hypotension
   • Evaluate ability to tolerate oral medications and maintain hydration
   • Consider ER referral if severe systemic symptoms or inability to take oral antibiotics

Important Considerations and Pitfalls

• Not all Lyme disease requires emergency care - Most cases of early Lyme disease with erythema migrans can be managed as outpatients with oral antibiotics 2
• Facial nerve palsy alone may not require emergency evaluation if the patient has no other neurological symptoms and can be treated with appropriate oral antibiotics 1, 4
• Lyme arthritis without systemic symptoms can typically be managed in the outpatient setting 1
• Avoid attributing all symptoms to Lyme disease - Consider other diagnoses that may require emergency care, especially in patients with atypical presentations 2
• Remember the possibility of co-infections - Patients with tick-borne diseases may have concurrent infections like anaplasmosis that can cause severe illness requiring emergency care 1

Follow-up Recommendations

• Patients treated for early Lyme disease as outpatients should be advised to seek emergency care if they develop:
  • New cardiac symptoms (palpitations, chest pain, syncope)
  • New neurological symptoms (severe headache, confusion, weakness)
  • Inability to take prescribed medications
  • Worsening symptoms despite appropriate antibiotic therapy

By following these guidelines, clinicians can appropriately triage patients with suspected Lyme disease, ensuring those with potentially life-threatening complications receive prompt emergency evaluation while managing less severe cases in the outpatient setting.