How does Lyme disease manifest after a tick bite? - briefly
Typically, infection appears within 3–30 days as an expanding red rash (erythema migrans) often accompanied by fever, chills, headache, fatigue, and muscle aches. If untreated, it can progress to joint swelling, neurological disturbances, or cardiac involvement.
How does Lyme disease manifest after a tick bite? - in detail
Lyme disease typically emerges in stages after a bite from an infected Ixodes tick. The first clinical sign appears within 3–30 days and is most often a skin lesion known as erythema migrans. This expanding erythematous rash has a characteristic “bull’s‑eye” appearance, may reach 5–30 cm in diameter, and is usually painless. Accompanying systemic symptoms frequently include low‑grade fever, fatigue, headache, myalgia, and arthralgia.
If untreated, the infection can spread hematogenously, producing early disseminated manifestations between 2 weeks and several months post‑exposure. Neurological involvement may present as facial nerve palsy, meningitis, or radiculopathy, often accompanied by neck stiffness and photophobia. Cardiac involvement appears as atrioventricular conduction abnormalities, most commonly first‑degree AV block, sometimes progressing to higher‑grade block. Transient migratory erythema migrans lesions may develop at distant sites.
Late manifestations arise months to years after the initial bite. The hallmark is chronic arthritis, typically affecting large joints such as the knee, with intermittent swelling, warmth, and pain. Persistent neurologic complaints can include peripheral neuropathy, encephalopathy, and cognitive deficits. Serologic testing (ELISA followed by Western blot) becomes more reliable in this phase, while polymerase chain reaction of synovial fluid may aid diagnosis of arthritis.
Key timelines and features:
- 3–30 days: Erythema migrans, flu‑like symptoms.
- 2 weeks–3 months: Multiple rashes, cranial nerve palsy, meningitis, AV block.
- ≥6 months: Migratory arthritis, chronic neurologic deficits.
Prompt antibiotic therapy (doxycycline, amoxicillin, or cefuroxime) during the early stage reduces risk of dissemination and long‑term complications. Monitoring for cardiac conduction disturbances and joint inflammation is essential throughout the disease course.