According to estimates, 3,000–4,000 people in Finland contract early-stage Lyme disease each year. If the early stage is not treated with antibiotics, approximately half of the patients develop later symptoms of the disease, which can be diverse and severe and cause permanent changes.
Symptoms of early-stage Lyme disease
Early-stage symptoms of Lyme disease are typically skin changes. Lyme disease is accompanied by erythema migrans, which is a circular rash. Sometimes a red or blue soft lymphocytoma, a benign tumour, may appear on the skin. Symptoms of arthritis may also be associated with the early stage.
Skin symptoms of Lyme disease:
- Lyme disease rash. A ring-shaped or evenly flush rash with a diameter of more than 5 cm begins to spread over the bite site of the tick.
- Lymphocytoma. A red or blue soft benign tumour may appear on the skin.
You should see a doctor if you notice early-stage symptoms of Lyme disease, as they can usually be treated with antibiotics.
Symptoms of late-stage Lyme disease
If Lyme disease is left untreated at an early stage, the bacteria can spread from the skin to other parts of the body. The symptoms of late-stage Lyme disease are diverse and can occur in one or more organs after weeks, months or even years. The skin, brain, nerves and joints are the most common areas affected by the disease.
- Joint symptoms. Up to half of patients experience joint symptoms, but only one in five develops clear joint swelling inflammation, or arthritis. It is typical that the joint symptoms caused by Lyme disease vary and there are asymptomatic and symptomatic periods. The symptoms may resemble rheumatism. Usually only a few large joints, such as the knee or ankle joint, are affected.
- Meningitis. Lyme disease also quite often causes meningitis, which can recur. However, the inflammation may be milder than that caused by other bacteria and may cause very few symptoms. Borrelia can also nest in the brain tissue itself.
- Cardiac symptoms. Cardiac symptoms may also occur, but are less common as they occur in less than 10% of patients. Cardiac symptoms typically appear within a few months of the tick bite. Borrelia can cause a sudden bradycardia phase, which may even require a temporary pacemaker. Lyme disease can sometimes also manifest as silent myocarditis.