Lyme Disease
Also known as Lyme borreliosis
This article is general health information for the selected condition. It is not a diagnosis and does not replace clinical judgement. If you have questions or need treatment advice, please consult a qualified healthcare professional.
What is lyme disease?
Lyme disease is caused by Borrelia bacteria transmitted through the bite of an infected tick. The classic early sign is an expanding circular rash at the bite site. Treated early with antibiotics, outcomes are excellent, whereas untreated infection can spread to joints, the nervous system and the heart.
Causes
- Borrelia burgdorferi and related species
- Transmission by Ixodes ticks
- Prolonged tick attachment, usually over 24 to 36 hours
Symptoms
- Expanding circular rash, often with central clearing
- Flu like illness with fever, headache and fatigue
- Muscle and joint aches
- Swollen lymph nodes
- Facial nerve palsy in later disease
- Joint swelling, typically the knee
- Nerve pain or numbness
- Palpitations from heart block in rare cases
Risk factors
- Outdoor activity in wooded or grassy areas
- Living in or visiting endemic regions
- Occupational exposure such as forestry
- Not performing tick checks after outdoor activity
- Late spring to early autumn exposure
Diagnosis
- Clinical diagnosis when the characteristic rash is present
- Two tier serology with ELISA followed by immunoblot
- Awareness that antibodies take weeks to develop
- Lumbar puncture for suspected neurological involvement
- ECG if cardiac symptoms are present
Treatment
- Doxycycline as first line in adults
- Amoxicillin or cefuroxime as alternatives
- Intravenous ceftriaxone for neurological or cardiac disease
- Prompt correct tick removal with fine tipped tweezers
- Single dose prophylaxis after high risk bites in some settings
- Symptomatic support for lingering fatigue
Self care
- Remove ticks promptly with fine tipped tweezers, pulling straight up
- Do not burn the tick or apply petroleum jelly
- Clean the bite area afterwards
- Photograph any expanding rash to show your doctor
- Complete the full antibiotic course
- Check the whole body after outdoor activity, including scalp and skin folds
When to see a doctor
Book an appointment if:
- An expanding circular rash after a tick bite
- Flu like illness following outdoor activity in an endemic area
- Joint swelling weeks after a bite
- Facial weakness or nerve pain
- Palpitations or unusual fatigue after a bite
- A tick attached for more than 36 hours
Some symptoms need emergency care rather than an appointment. See the warning signs listed above.
Prevention
- Wear long sleeves and trousers in wooded and grassy areas
- Use insect repellent containing DEET on skin and permethrin on clothing
- Stay on paths and avoid brushing through vegetation
- Check yourself, children and pets after being outdoors
- Remove ticks within 24 hours
- Shower soon after outdoor activity
Outlook
Treated early with antibiotics, Lyme disease resolves completely in the large majority. Later stage disease with joint, neurological or cardiac involvement usually still responds but may take longer. Some people report lingering fatigue and aches for months afterwards, which does not indicate ongoing infection and does not respond to further antibiotics.
Common questions
How should a tick be removed?
Grasp it as close to the skin as possible with fine tipped tweezers and pull steadily upward without twisting. Do not burn it or apply petroleum jelly, which can increase the chance of transmission.
Does every tick bite cause Lyme disease?
No. Only a proportion of ticks carry the bacteria, and transmission usually requires attachment for a day or more. Prompt removal substantially reduces risk.
Is a blood test useful immediately after a bite?
No. Antibodies take several weeks to appear, so early testing is often falsely negative. If the characteristic expanding rash is present, treatment is started on clinical grounds without waiting for serology.
References
Important: Dard AI is not a medical device and does not diagnose, treat, or replace clinician judgement. This article is general information only. Always consult a qualified healthcare professional about diagnosis and treatment, and seek emergency care for severe or rapidly worsening symptoms.