Lyme Disease

Lyme disease, also known as Lyme borreliosis, is a tick-borne illness caused by the Borrelia bacteria, primarily spread by ticks of the genus Ixodes. In the UK, the key species responsible is Ixodes ricinus. Understanding Lyme disease is very important for healthcare professionals as it can present with multi-system involvement and a variety of symptoms.

Signs and Symptoms

The initial symptom of Lyme disease is often an expanding red rash called erythema migrans (EM), which appears at the site of the tick bite about a week later. The rash is typically neither itchy nor painful. Around 70-80% of infected individuals develop this rash. Early symptoms also include fever, headaches, and fatigue.

If untreated, the disease can progress, leading to complications such as facial palsy, arthritis, severe headaches, neck stiffness, and heart palpitations. Months to years later, joint pain, swelling, shooting pains, and tingling in the arms and legs may develop. Despite appropriate treatment, about 10 to 20% of those affected develop post-treatment Lyme disease syndrome (PTLDS) characterised by joint pains, memory problems, and tiredness for six months or more.

Diagnosis

Diagnosis of Lyme disease is based on a combination of clinical symptoms, history of tick exposure, and laboratory tests. The EM rash and a history of tick exposure are often sufficient for diagnosis without further testing.

Blood tests to detect antibodies against Borrelia are commonly used but may give false-negative results in the early stages of the disease. Advanced diagnostic methods like polymerase chain reaction (PCR) tests for Borrelia DNA and cerebrospinal fluid (CSF) analysis for neuroborreliosis are also available but are used selectively.

Treatment

The primary treatment for Lyme disease involves antibiotics. Early localised infections are typically treated with oral doxycycline, amoxicillin, or cefuroxime. In cases of disseminated or late-stage Lyme disease with cardiac or neurological involvement, intravenous antibiotics like ceftriaxone are recommended.

Treatment duration ranges from 14 days for early disease to 28 days for more severe cases. Corticosteroids are not recommended for Lyme disease, especially for facial palsy or Lyme carditis. Post-antibiotic Lyme arthritis, a condition where joint swelling persists despite antibiotic treatment, may require nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying antirheumatic drugs (DMARDs), or physical therapy.

Prevention

Prevention of Lyme disease focuses on avoiding tick bites. Protective measures include wearing long clothing, using tick repellents such as DEET or picaridin, and treating clothes with permethrin. After potential exposure, checking for ticks and prompt removal of any found is very important, as the risk of transmission increases significantly after 36 hours of tick attachment.

Removing ticks involves using fine-tipped tweezers to pull them straight out without twisting or crushing. Preventive antibiotics are recommended in specific high-risk cases, such as when a tick has been attached for over 36 hours and is engorged.

Vaccination

As of 2023, no human vaccines for Lyme disease are available. The only vaccine, LYMErix, was discontinued in 2002 due to insufficient demand and safety concerns. A new vaccine candidate, VLA15, is undergoing clinical trials. Several vaccines are available for dogs.

Epidemiology

Lyme disease is most common in the Northern Hemisphere, particularly in temperate regions. In the UK, it is most prevalent in areas with high tick populations, including the New Forest, South Downs, and parts of Scotland. Awareness and preventive measures are very important to managing the disease's spread and impact.

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Self-assessment MCQs (single best answer)

What is the primary cause of Lyme disease?

Which tick species is primarily responsible for spreading Lyme disease in the UK?

What is the name of the characteristic rash associated with early Lyme disease?

Which of the following symptoms is NOT typically associated with early Lyme disease?

What is the first-line treatment for early localised Lyme disease?

How long after tick attachment does the risk of Borrelia transmission significantly increase?

Which of the following is NOT a preventive measure for Lyme disease?

What is the term for persistent symptoms lasting six months or more after treatment for Lyme disease?

Which diagnostic method is commonly used but may give false-negative results in the early stages of Lyme disease?

Which of the following statements about the Lyme disease vaccine is TRUE as of 2023?