Lyme disease

What it is

Lyme disease is caused by B. burgdorferi. Transmission is by hard ticks of the Ixodes group; deer and moose are the hosts, and cases are common in summer and in rural areas.

How it presents

The acute stage begins at the bite site. An erythematous macula appears where the tick fed and expands into erythema migrans, which is painless, red and edematous with a bright red outer edge; the rash is circular and may come with itching. With it come fever, malaise, myalgia and lymphadenopathy, and a flu-like set of headache, fatigue, chills, sore throat and muscle aches.

In the latent stage the disease shows itself elsewhere:

• Neurological: bilateral facial nerve palsies, meningitis and peripheral neuropathy. Hearing loss is also described.
• Cardiac: myocarditis, with a rapid or slow heart rate, syncope and dyspnea.
• Joint: migratory arthralgia and monoarthritic disease, with hot and swollen joints.
• In the long term: depression and dementia. Insomnia is described as well.