Lyme disease Flashcards
What causes Lyme disease?
Lyme disease is caused by the spirochaete Borrelia burgdorferi and is spread by ticks.
What is erythema migrans?
Erythema migrans is a ‘bulls-eye’ rash typically at the site of the tick bite, usually painless, more than 5 cm in diameter, and slowly increases in size.
When does erythema migrans typically develop?
Erythema migrans typically develops 1-4 weeks after the initial tick bite but may present sooner.
What percentage of Lyme disease patients present with erythema migrans?
Erythema migrans is present in around 80% of patients.
What are early systemic features of Lyme disease?
Early systemic features include headache, lethargy, fever, and arthralgia.
What cardiovascular features may occur after 30 days of Lyme disease?
Cardiovascular features may include heart block and peri/myocarditis.
What neurological features may occur after 30 days of Lyme disease?
Neurological features may include facial nerve palsy, radicular pain, and meningitis.
How can Lyme disease be diagnosed clinically?
Lyme disease can be diagnosed clinically if erythema migrans is present.
What is the first-line test for Lyme disease?
The first-line test is an enzyme-linked immunosorbent assay (ELISA) for antibodies to Borrelia burgdorferi.
What should be done if the first ELISA test is negative but Lyme disease is still suspected?
If negative and Lyme disease is still suspected, repeat the ELISA 4-6 weeks after the first test.
What is the recommended management for asymptomatic tick bites?
If the tick is still present, remove it using fine-tipped tweezers and wash the area. Routine antibiotic treatment is not recommended.
What is the first-line antibiotic for suspected or confirmed early Lyme disease?
Doxycycline is the first-line antibiotic for early Lyme disease.
What alternative antibiotic can be used if doxycycline is contraindicated?
Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy).
What should be given for disseminated Lyme disease?
Ceftriaxone should be given for disseminated Lyme disease.
What is the Jarisch-Herxheimer reaction?
The Jarisch-Herxheimer reaction is sometimes seen after initiating therapy, presenting as fever, rash, and tachycardia after the first dose of antibiotic.
