Lyme disease

Question 1

Lyme Disease

Answer 1

• This disease, caused by the spirochaete Borrelia burgdorferi, was first recognised in 1975 in a cluster of children with arthritis in Lyme, Connecticut.
• It occurs in the UK. Borrelia burgdorferi is transmitted by the hard tick, which has a range of hosts but favours deer and moose.
• Infections occur most commonly in the summer months in susceptible persons in rural settings

Question 2

Lyme Disease

Clinical features

Answer 2

• Following an incubation period of 4–20 days, an erythematous macule at the site of the tick bite enlarges to cause the classical skin lesion known as erythema migrans, a painless red expanding lesion with a bright red outer spreading edge
• During early disease, the skin lesion is often accompanied by fever, headache, malaise, myalgia, arthralgia and lymphadenopathy. Usually, these features fluctuate over several weeks and then resolve.
• late stage of Lyme disease occurs after weeks to months with neurological, cardiac and joint manifestations.
• Neurological disease includes meningoencephalitis and cranial (particularly facial nerve) and peripheral neuropathies.
• Cardiac disease includes myocarditis and heart block. Joint disease occurs in about 50% and varies from brief migratory arthralgia to acute asymmetric mono- and oligoarthritis of the large joints.
• Recurrent attacks of arthritis are common. In 10%, chronic erosive joint disease occurs months to years after the initial attack

Question 3

Lyme Disease

Treatment

Answer 3

The drug of choice for early uncomplicated cases over 12 years of age is doxycycline, and for younger children, amoxicillin. Intravenous treatment with ceftriaxone is required for carditis or neurological disease