Lyme Disease

What is lyme disease caused by

• Borrelia burgdorferi

Lyme disease is transferred by deer ticks, aka

Ixodes scapularis

What makes a tick bite "high-risk" for Lyme disease?

• The tick is from the Ixodes species

• The bite happened in a highly endemic area

• The tick was attached for ≥36 hours

What do we do for a high-risk bite?

• Doxycycline 200 mg, just one dose

• Must be taken within 72 hours (3 days) of removing the tick

• This is called prophylaxis (prevention treatment) to stop Lyme disease before it starts

Lyme disease Symptoms

• Neurologic

• Cardiac

• Musculoskeletal

• Skin (Erythema migrans = bull’s-eye rash 🎯)

• Constitutional (Fever, chills, fatigue, weakness)

Most patients present with this symptom with Lyme Disease

• Erythema migrans Rash (bull’s eye rash)

Patients with lyme disease develop Erythema migrans Rash symptom _____________ after removal of tick

• 3 to 30 days

Early Lyme (3–30 days after bite):

• Erythema Migrans rash

• Flu-like symptoms: fever, chills, headache, muscle/joint pain, fatigue

• Rash starts small and expands, often warm but not itchy or painful

Late Lyme (days to months after)

• Facial palsy

• Arthritis with severe joint pain and swelling, especially knees

• Severe headaches and neck stiffness

• Additional EM rashes on other areas of the body

• Carditis and heart block

• Neurologic abnormalities; fatigue, shooting pains, numbness

Erythema Migrans

• A round or oval, slowly expanding red rash

• Must be at least 5 cm in size

• Develops at the site of a tick bite

• Timeline After Tick Removal:

  • < 72 hours → Hypersensitivity reaction (allergic) — fades in 24–48 hrs

  • ≥ 72 hours → Erythema Migrans → Lyme Disease (rash grows over 7–14 days)

Management of Suspected Lyme

• Resolve symptoms of early Lyme

• Eradicate Borrelia infection

• Prevent long-term complications

• Minimize adverse effects and healthcare costs

• Prophylaxis (for high-risk tick bite):

  • Must be given within 72 hours of tick removal

  • Give Doxycycline 200 mg PO x 1 dose

• Treatment:

  • Depends on the clinical presentation

  • Next step: decide PO vs IV therapy depending on how severe it is

Early Lyme Disease - Treatment

• Doxycycline PO× 10 days

  → In the absence of neurologic symptoms or heart block

Severe Presentation/ Requiring Hospital Lyme Disease - Treatment

• Ceftriaxone (2g IV once daily)

→ Patients with neurologic or cardiac symptoms may require hospitalization