Borreliosis (Lyme disease): symptoms and signs by stage

Borreliosis, or Lyme disease, is a bacterial infection transmitted through the bite of an infected tick. The earlier the diagnosis is made, the easier the treatment, so the picture by stage helps to understand what is happening. Below are the signs of the early and late phases.

What borreliosis and Lyme disease are

This is a vector-borne infection: spirochetes of the genus Borrelia enter the blood when an infected ixodid tick bites. In the USA, the main causative agent is Borrelia burgdorferi, and the vector is the black-legged (deer) tick; in Europe, it is Ixodes ricinus and Ixodes persulcatus. Lyme disease is the most common disease transmitted by ticks.

The tick attaches in inconspicuous places — the groin, armpits, and scalp. To transmit the bacterium, it usually needs to remain attached for more than 24 hours. Most bites occur from April to September, but in a warm winter ticks are active earlier. Not all ticks are infected.

First signs of borreliosis after a tick bite

Early symptoms begin 3–30 days after the bite. The main marker is erythema migrans: a round or oval patch around the bite site. It usually appears after 1–4 weeks (at most, up to 3 months), persists for several weeks, and gradually grows. The center may be lighter or darker, and the edges slightly raised. The patch is more often not hot and not itchy, may be flat or slightly raised, and pink, red, or purple on light skin. On dark skin it is harder to notice: sometimes it resembles a bruise. The classic appearance is a "target".

At the same time, there may be flu-like signs: fever and chills, headache, muscle and joint pain, fatigue, and enlarged lymph nodes. It is recommended to check children and pets regularly for ticks after outdoor walks.

Symptoms of late stages and chronic borreliosis

Without treatment, the infection spreads to the joints, heart, and nervous system. Severe manifestations occur months or years later, more often when treatment is delayed: joint pain and swelling (especially of the knees), migratory pain in tendons, muscles, and bones, heart palpitations and arrhythmias (Lyme carditis), dizziness and shortness of breath, problems with memory and concentration, and recurrent erythemas on other parts of the body.

In some treated patients, fatigue, pain, and difficulty thinking persist for longer than 6 months — this is post-treatment Lyme disease syndrome (PTLDS). Its causes are unknown, and long courses of antibiotics do not help. Specialists consider the diagnosis of "chronic borreliosis" controversial: such patients often do not have the causative agent, and similar symptoms occur in fibromyalgia and chronic fatigue syndrome.

Neuroborreliosis: which symptoms are linked to the nervous system

Nervous system involvement is one of the manifestations of disseminated infection:

• facial palsy — weakness of the facial muscles with drooping of one or both corners;
• shooting pain, numbness, or tingling in the arms and feet;
• severe headaches and neck stiffness;
• inflammation of the brain and spinal cord;
• worsening memory and concentration.

Can borreliosis occur without symptoms, and how is it detected

Yes. There is a non-erythematous form — with fever and intoxication but without a rash — and a latent form, when laboratory confirmation is present but there are no signs of the disease. Diagnosis is not simple: the symptoms resemble other conditions, and erythema is not always visible. The doctor asks about complaints, bites, and time spent in forested and grassy areas, and examines the skin.

Confirmation is by two types of blood antibody tests. In the first weeks they may be false-negative: antibodies take several weeks to develop, so if symptoms persist after a negative result, the test is repeated. Tests and "treatment" from the internet without scientific evidence are a reason to talk to a doctor first.

When to see a doctor

You should see a doctor urgently if within the last 3 months there was a tick bite or time spent in an area with infected ticks and one of the two has appeared: a round or oval patch or a flu-like malaise — fever, chills, headache, aching muscles. For late complaints — joint pain, neurological or cardiac symptoms — a consultation is also needed.

Borreliosis itself is not a reason to call an ambulance. 103 or 112 — for signs of stroke or heart attack, as well as for a life-threatening condition.

This material is for reference: it describes signs by stage but does not replace a doctor's examination — decisions about diagnosis and care are made after consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer